TUN-6772: Add a JWT Validator as an ingress verifier

This adds a new verifier interface that can be attached to ingress.Rule.
This would act as a middleware layer that gets executed at the start of
proxy.ProxyHTTP.

A jwt validator implementation for this verifier is also provided. The
validator downloads the public key from the access teams endpoint and
uses it to verify the JWT sent to cloudflared with the audtag (clientID)
information provided in the config.

vendor/google.golang.org/grpc/balancer/balancer.go

@@ -27,6 +27,7 @@ import (
 	"net"
 	"strings"
 
+	"google.golang.org/grpc/channelz"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal"
@@ -192,7 +193,7 @@ type BuildOptions struct {
 	// server can ignore this field.
 	Authority string
 	// ChannelzParentID is the parent ClientConn's channelz ID.
-	ChannelzParentID int64
+	ChannelzParentID *channelz.Identifier
 	// CustomUserAgent is the custom user agent set on the parent ClientConn.
 	// The balancer should set the same custom user agent if it creates a
 	// ClientConn.

vendor/google.golang.org/grpc/balancer_conn_wrappers.go

@@ -20,130 +20,178 @@ package grpc
 
 import (
 	"fmt"
+	"strings"
 	"sync"
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/internal/balancer/gracefulswitch"
 	"google.golang.org/grpc/internal/buffer"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/resolver"
 )
 
-// scStateUpdate contains the subConn and the new state it changed to.
+// ccBalancerWrapper sits between the ClientConn and the Balancer.
+//
+// ccBalancerWrapper implements methods corresponding to the ones on the
+// balancer.Balancer interface. The ClientConn is free to call these methods
+// concurrently and the ccBalancerWrapper ensures that calls from the ClientConn
+// to the Balancer happen synchronously and in order.
+//
+// ccBalancerWrapper also implements the balancer.ClientConn interface and is
+// passed to the Balancer implementations. It invokes unexported methods on the
+// ClientConn to handle these calls from the Balancer.
+//
+// It uses the gracefulswitch.Balancer internally to ensure that balancer
+// switches happen in a graceful manner.
+type ccBalancerWrapper struct {
+	cc *ClientConn
+
+	// Since these fields are accessed only from handleXxx() methods which are
+	// synchronized by the watcher goroutine, we do not need a mutex to protect
+	// these fields.
+	balancer        *gracefulswitch.Balancer
+	curBalancerName string
+
+	updateCh *buffer.Unbounded // Updates written on this channel are processed by watcher().
+	resultCh *buffer.Unbounded // Results of calls to UpdateClientConnState() are pushed here.
+	closed   *grpcsync.Event   // Indicates if close has been called.
+	done     *grpcsync.Event   // Indicates if close has completed its work.
+}
+
+// newCCBalancerWrapper creates a new balancer wrapper. The underlying balancer
+// is not created until the switchTo() method is invoked.
+func newCCBalancerWrapper(cc *ClientConn, bopts balancer.BuildOptions) *ccBalancerWrapper {
+	ccb := &ccBalancerWrapper{
+		cc:       cc,
+		updateCh: buffer.NewUnbounded(),
+		resultCh: buffer.NewUnbounded(),
+		closed:   grpcsync.NewEvent(),
+		done:     grpcsync.NewEvent(),
+	}
+	go ccb.watcher()
+	ccb.balancer = gracefulswitch.NewBalancer(ccb, bopts)
+	return ccb
+}
+
+// The following xxxUpdate structs wrap the arguments received as part of the
+// corresponding update. The watcher goroutine uses the 'type' of the update to
+// invoke the appropriate handler routine to handle the update.
+
+type ccStateUpdate struct {
+	ccs *balancer.ClientConnState
+}
+
 type scStateUpdate struct {
 	sc    balancer.SubConn
 	state connectivity.State
 	err   error
 }
 
-// exitIdle contains no data and is just a signal sent on the updateCh in
-// ccBalancerWrapper to instruct the balancer to exit idle.
-type exitIdle struct{}
+type exitIdleUpdate struct{}
 
-// ccBalancerWrapper is a wrapper on top of cc for balancers.
-// It implements balancer.ClientConn interface.
-type ccBalancerWrapper struct {
-	cc          *ClientConn
-	balancerMu  sync.Mutex // synchronizes calls to the balancer
-	balancer    balancer.Balancer
-	hasExitIdle bool
-	updateCh    *buffer.Unbounded
-	closed      *grpcsync.Event
-	done        *grpcsync.Event
-
-	mu       sync.Mutex
-	subConns map[*acBalancerWrapper]struct{}
+type resolverErrorUpdate struct {
+	err error
 }
 
-func newCCBalancerWrapper(cc *ClientConn, b balancer.Builder, bopts balancer.BuildOptions) *ccBalancerWrapper {
-	ccb := &ccBalancerWrapper{
-		cc:       cc,
-		updateCh: buffer.NewUnbounded(),
-		closed:   grpcsync.NewEvent(),
-		done:     grpcsync.NewEvent(),
-		subConns: make(map[*acBalancerWrapper]struct{}),
-	}
-	go ccb.watcher()
-	ccb.balancer = b.Build(ccb, bopts)
-	_, ccb.hasExitIdle = ccb.balancer.(balancer.ExitIdler)
-	return ccb
+type switchToUpdate struct {
+	name string
 }
 
-// watcher balancer functions sequentially, so the balancer can be implemented
-// lock-free.
+type subConnUpdate struct {
+	acbw *acBalancerWrapper
+}
+
+// watcher is a long-running goroutine which reads updates from a channel and
+// invokes corresponding methods on the underlying balancer. It ensures that
+// these methods are invoked in a synchronous fashion. It also ensures that
+// these methods are invoked in the order in which the updates were received.
 func (ccb *ccBalancerWrapper) watcher() {
 	for {
 		select {
-		case t := <-ccb.updateCh.Get():
+		case u := <-ccb.updateCh.Get():
 			ccb.updateCh.Load()
 			if ccb.closed.HasFired() {
 				break
 			}
-			switch u := t.(type) {
+			switch update := u.(type) {
+			case *ccStateUpdate:
+				ccb.handleClientConnStateChange(update.ccs)
 			case *scStateUpdate:
-				ccb.balancerMu.Lock()
-				ccb.balancer.UpdateSubConnState(u.sc, balancer.SubConnState{ConnectivityState: u.state, ConnectionError: u.err})
-				ccb.balancerMu.Unlock()
-			case *acBalancerWrapper:
-				ccb.mu.Lock()
-				if ccb.subConns != nil {
-					delete(ccb.subConns, u)
-					ccb.cc.removeAddrConn(u.getAddrConn(), errConnDrain)
-				}
-				ccb.mu.Unlock()
-			case exitIdle:
-				if ccb.cc.GetState() == connectivity.Idle {
-					if ei, ok := ccb.balancer.(balancer.ExitIdler); ok {
-						// We already checked that the balancer implements
-						// ExitIdle before pushing the event to updateCh, but
-						// check conditionally again as defensive programming.
-						ccb.balancerMu.Lock()
-						ei.ExitIdle()
-						ccb.balancerMu.Unlock()
-					}
-				}
+				ccb.handleSubConnStateChange(update)
+			case *exitIdleUpdate:
+				ccb.handleExitIdle()
+			case *resolverErrorUpdate:
+				ccb.handleResolverError(update.err)
+			case *switchToUpdate:
+				ccb.handleSwitchTo(update.name)
+			case *subConnUpdate:
+				ccb.handleRemoveSubConn(update.acbw)
 			default:
-				logger.Errorf("ccBalancerWrapper.watcher: unknown update %+v, type %T", t, t)
+				logger.Errorf("ccBalancerWrapper.watcher: unknown update %+v, type %T", update, update)
 			}
 		case <-ccb.closed.Done():
 		}
 
 		if ccb.closed.HasFired() {
-			ccb.balancerMu.Lock()
-			ccb.balancer.Close()
-			ccb.balancerMu.Unlock()
-			ccb.mu.Lock()
-			scs := ccb.subConns
-			ccb.subConns = nil
-			ccb.mu.Unlock()
-			ccb.UpdateState(balancer.State{ConnectivityState: connectivity.Connecting, Picker: nil})
-			ccb.done.Fire()
-			// Fire done before removing the addr conns.  We can safely unblock
-			// ccb.close and allow the removeAddrConns to happen
-			// asynchronously.
-			for acbw := range scs {
-				ccb.cc.removeAddrConn(acbw.getAddrConn(), errConnDrain)
-			}
+			ccb.handleClose()
 			return
 		}
 	}
 }
 
-func (ccb *ccBalancerWrapper) close() {
-	ccb.closed.Fire()
-	<-ccb.done.Done()
-}
+// updateClientConnState is invoked by grpc to push a ClientConnState update to
+// the underlying balancer.
+//
+// Unlike other methods invoked by grpc to push updates to the underlying
+// balancer, this method cannot simply push the update onto the update channel
+// and return. It needs to return the error returned by the underlying balancer
+// back to grpc which propagates that to the resolver.
+func (ccb *ccBalancerWrapper) updateClientConnState(ccs *balancer.ClientConnState) error {
+	ccb.updateCh.Put(&ccStateUpdate{ccs: ccs})
 
-func (ccb *ccBalancerWrapper) exitIdle() bool {
-	if !ccb.hasExitIdle {
-		return false
+	var res interface{}
+	select {
+	case res = <-ccb.resultCh.Get():
+		ccb.resultCh.Load()
+	case <-ccb.closed.Done():
+		// Return early if the balancer wrapper is closed while we are waiting for
+		// the underlying balancer to process a ClientConnState update.
+		return nil
 	}
-	ccb.updateCh.Put(exitIdle{})
-	return true
+	// If the returned error is nil, attempting to type assert to error leads to
+	// panic. So, this needs to handled separately.
+	if res == nil {
+		return nil
+	}
+	return res.(error)
 }
 
-func (ccb *ccBalancerWrapper) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State, err error) {
+// handleClientConnStateChange handles a ClientConnState update from the update
+// channel and invokes the appropriate method on the underlying balancer.
+//
+// If the addresses specified in the update contain addresses of type "grpclb"
+// and the selected LB policy is not "grpclb", these addresses will be filtered
+// out and ccs will be modified with the updated address list.
+func (ccb *ccBalancerWrapper) handleClientConnStateChange(ccs *balancer.ClientConnState) {
+	if ccb.curBalancerName != grpclbName {
+		// Filter any grpclb addresses since we don't have the grpclb balancer.
+		var addrs []resolver.Address
+		for _, addr := range ccs.ResolverState.Addresses {
+			if addr.Type == resolver.GRPCLB {
+				continue
+			}
+			addrs = append(addrs, addr)
+		}
+		ccs.ResolverState.Addresses = addrs
+	}
+	ccb.resultCh.Put(ccb.balancer.UpdateClientConnState(*ccs))
+}
+
+// updateSubConnState is invoked by grpc to push a subConn state update to the
+// underlying balancer.
+func (ccb *ccBalancerWrapper) updateSubConnState(sc balancer.SubConn, s connectivity.State, err error) {
 	// When updating addresses for a SubConn, if the address in use is not in
 	// the new addresses, the old ac will be tearDown() and a new ac will be
 	// created. tearDown() generates a state change with Shutdown state, we
@@ -161,44 +209,125 @@ func (ccb *ccBalancerWrapper) handleSubConnStateChange(sc balancer.SubConn, s co
 	})
 }
 
-func (ccb *ccBalancerWrapper) updateClientConnState(ccs *balancer.ClientConnState) error {
-	ccb.balancerMu.Lock()
-	defer ccb.balancerMu.Unlock()
-	return ccb.balancer.UpdateClientConnState(*ccs)
+// handleSubConnStateChange handles a SubConnState update from the update
+// channel and invokes the appropriate method on the underlying balancer.
+func (ccb *ccBalancerWrapper) handleSubConnStateChange(update *scStateUpdate) {
+	ccb.balancer.UpdateSubConnState(update.sc, balancer.SubConnState{ConnectivityState: update.state, ConnectionError: update.err})
+}
+
+func (ccb *ccBalancerWrapper) exitIdle() {
+	ccb.updateCh.Put(&exitIdleUpdate{})
+}
+
+func (ccb *ccBalancerWrapper) handleExitIdle() {
+	if ccb.cc.GetState() != connectivity.Idle {
+		return
+	}
+	ccb.balancer.ExitIdle()
 }
 
 func (ccb *ccBalancerWrapper) resolverError(err error) {
-	ccb.balancerMu.Lock()
-	defer ccb.balancerMu.Unlock()
+	ccb.updateCh.Put(&resolverErrorUpdate{err: err})
+}
+
+func (ccb *ccBalancerWrapper) handleResolverError(err error) {
 	ccb.balancer.ResolverError(err)
 }
 
+// switchTo is invoked by grpc to instruct the balancer wrapper to switch to the
+// LB policy identified by name.
+//
+// ClientConn calls newCCBalancerWrapper() at creation time. Upon receipt of the
+// first good update from the name resolver, it determines the LB policy to use
+// and invokes the switchTo() method. Upon receipt of every subsequent update
+// from the name resolver, it invokes this method.
+//
+// the ccBalancerWrapper keeps track of the current LB policy name, and skips
+// the graceful balancer switching process if the name does not change.
+func (ccb *ccBalancerWrapper) switchTo(name string) {
+	ccb.updateCh.Put(&switchToUpdate{name: name})
+}
+
+// handleSwitchTo handles a balancer switch update from the update channel. It
+// calls the SwitchTo() method on the gracefulswitch.Balancer with a
+// balancer.Builder corresponding to name. If no balancer.Builder is registered
+// for the given name, it uses the default LB policy which is "pick_first".
+func (ccb *ccBalancerWrapper) handleSwitchTo(name string) {
+	// TODO: Other languages use case-insensitive balancer registries. We should
+	// switch as well. See: https://github.com/grpc/grpc-go/issues/5288.
+	if strings.EqualFold(ccb.curBalancerName, name) {
+		return
+	}
+
+	// TODO: Ensure that name is a registered LB policy when we get here.
+	// We currently only validate the `loadBalancingConfig` field. We need to do
+	// the same for the `loadBalancingPolicy` field and reject the service config
+	// if the specified policy is not registered.
+	builder := balancer.Get(name)
+	if builder == nil {
+		channelz.Warningf(logger, ccb.cc.channelzID, "Channel switches to new LB policy %q, since the specified LB policy %q was not registered", PickFirstBalancerName, name)
+		builder = newPickfirstBuilder()
+	} else {
+		channelz.Infof(logger, ccb.cc.channelzID, "Channel switches to new LB policy %q", name)
+	}
+
+	if err := ccb.balancer.SwitchTo(builder); err != nil {
+		channelz.Errorf(logger, ccb.cc.channelzID, "Channel failed to build new LB policy %q: %v", name, err)
+		return
+	}
+	ccb.curBalancerName = builder.Name()
+}
+
+// handleRemoveSucConn handles a request from the underlying balancer to remove
+// a subConn.
+//
+// See comments in RemoveSubConn() for more details.
+func (ccb *ccBalancerWrapper) handleRemoveSubConn(acbw *acBalancerWrapper) {
+	ccb.cc.removeAddrConn(acbw.getAddrConn(), errConnDrain)
+}
+
+func (ccb *ccBalancerWrapper) close() {
+	ccb.closed.Fire()
+	<-ccb.done.Done()
+}
+
+func (ccb *ccBalancerWrapper) handleClose() {
+	ccb.balancer.Close()
+	ccb.done.Fire()
+}
+
 func (ccb *ccBalancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
 	if len(addrs) <= 0 {
 		return nil, fmt.Errorf("grpc: cannot create SubConn with empty address list")
 	}
-	ccb.mu.Lock()
-	defer ccb.mu.Unlock()
-	if ccb.subConns == nil {
-		return nil, fmt.Errorf("grpc: ClientConn balancer wrapper was closed")
-	}
 	ac, err := ccb.cc.newAddrConn(addrs, opts)
 	if err != nil {
+		channelz.Warningf(logger, ccb.cc.channelzID, "acBalancerWrapper: NewSubConn: failed to newAddrConn: %v", err)
 		return nil, err
 	}
 	acbw := &acBalancerWrapper{ac: ac}
 	acbw.ac.mu.Lock()
 	ac.acbw = acbw
 	acbw.ac.mu.Unlock()
-	ccb.subConns[acbw] = struct{}{}
 	return acbw, nil
 }
 
 func (ccb *ccBalancerWrapper) RemoveSubConn(sc balancer.SubConn) {
-	// The RemoveSubConn() is handled in the run() goroutine, to avoid deadlock
-	// during switchBalancer() if the old balancer calls RemoveSubConn() in its
-	// Close().
-	ccb.updateCh.Put(sc)
+	// Before we switched the ccBalancerWrapper to use gracefulswitch.Balancer, it
+	// was required to handle the RemoveSubConn() method asynchronously by pushing
+	// the update onto the update channel. This was done to avoid a deadlock as
+	// switchBalancer() was holding cc.mu when calling Close() on the old
+	// balancer, which would in turn call RemoveSubConn().
+	//
+	// With the use of gracefulswitch.Balancer in ccBalancerWrapper, handling this
+	// asynchronously is probably not required anymore since the switchTo() method
+	// handles the balancer switch by pushing the update onto the channel.
+	// TODO(easwars): Handle this inline.
+	acbw, ok := sc.(*acBalancerWrapper)
+	if !ok {
+		return
+	}
+	ccb.updateCh.Put(&subConnUpdate{acbw: acbw})
 }
 
 func (ccb *ccBalancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver.Address) {
@@ -210,11 +339,6 @@ func (ccb *ccBalancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resol
 }
 
 func (ccb *ccBalancerWrapper) UpdateState(s balancer.State) {
-	ccb.mu.Lock()
-	defer ccb.mu.Unlock()
-	if ccb.subConns == nil {
-		return
-	}
 	// Update picker before updating state.  Even though the ordering here does
 	// not matter, it can lead to multiple calls of Pick in the common start-up
 	// case where we wait for ready and then perform an RPC.  If the picker is

vendor/google.golang.org/grpc/channelz/channelz.go

@@ -0,0 +1,36 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package channelz exports internals of the channelz implementation as required
+// by other gRPC packages.
+//
+// The implementation of the channelz spec as defined in
+// https://github.com/grpc/proposal/blob/master/A14-channelz.md, is provided by
+// the `internal/channelz` package.
+//
+// Experimental
+//
+// Notice: All APIs in this package are experimental and may be removed in a
+// later release.
+package channelz
+
+import "google.golang.org/grpc/internal/channelz"
+
+// Identifier is an opaque identifier which uniquely identifies an entity in the
+// channelz database.
+type Identifier = channelz.Identifier

vendor/google.golang.org/grpc/clientconn.go

@@ -159,23 +159,20 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *
 		}
 	}()
 
-	if channelz.IsOn() {
-		if cc.dopts.channelzParentID != 0 {
-			cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, cc.dopts.channelzParentID, target)
-			channelz.AddTraceEvent(logger, cc.channelzID, 0, &channelz.TraceEventDesc{
-				Desc:     "Channel Created",
-				Severity: channelz.CtInfo,
-				Parent: &channelz.TraceEventDesc{
-					Desc:     fmt.Sprintf("Nested Channel(id:%d) created", cc.channelzID),
-					Severity: channelz.CtInfo,
-				},
-			})
-		} else {
-			cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, 0, target)
-			channelz.Info(logger, cc.channelzID, "Channel Created")
-		}
-		cc.csMgr.channelzID = cc.channelzID
+	pid := cc.dopts.channelzParentID
+	cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, pid, target)
+	ted := &channelz.TraceEventDesc{
+		Desc:     "Channel created",
+		Severity: channelz.CtInfo,
 	}
+	if cc.dopts.channelzParentID != nil {
+		ted.Parent = &channelz.TraceEventDesc{
+			Desc:     fmt.Sprintf("Nested Channel(id:%d) created", cc.channelzID.Int()),
+			Severity: channelz.CtInfo,
+		}
+	}
+	channelz.AddTraceEvent(logger, cc.channelzID, 1, ted)
+	cc.csMgr.channelzID = cc.channelzID
 
 	if cc.dopts.copts.TransportCredentials == nil && cc.dopts.copts.CredsBundle == nil {
 		return nil, errNoTransportSecurity
@@ -281,7 +278,7 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *
 	if creds := cc.dopts.copts.TransportCredentials; creds != nil {
 		credsClone = creds.Clone()
 	}
-	cc.balancerBuildOpts = balancer.BuildOptions{
+	cc.balancerWrapper = newCCBalancerWrapper(cc, balancer.BuildOptions{
 		DialCreds:        credsClone,
 		CredsBundle:      cc.dopts.copts.CredsBundle,
 		Dialer:           cc.dopts.copts.Dialer,
@@ -289,7 +286,7 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *
 		CustomUserAgent:  cc.dopts.copts.UserAgent,
 		ChannelzParentID: cc.channelzID,
 		Target:           cc.parsedTarget,
-	}
+	})
 
 	// Build the resolver.
 	rWrapper, err := newCCResolverWrapper(cc, resolverBuilder)
@@ -398,7 +395,7 @@ type connectivityStateManager struct {
 	mu         sync.Mutex
 	state      connectivity.State
 	notifyChan chan struct{}
-	channelzID int64
+	channelzID *channelz.Identifier
 }
 
 // updateState updates the connectivity.State of ClientConn.
@@ -464,34 +461,36 @@ var _ ClientConnInterface = (*ClientConn)(nil)
 // handshakes. It also handles errors on established connections by
 // re-resolving the name and reconnecting.
 type ClientConn struct {
-	ctx    context.Context
-	cancel context.CancelFunc
+	ctx    context.Context    // Initialized using the background context at dial time.
+	cancel context.CancelFunc // Cancelled on close.
 
-	target       string
-	parsedTarget resolver.Target
-	authority    string
-	dopts        dialOptions
-	csMgr        *connectivityStateManager
-
-	balancerBuildOpts balancer.BuildOptions
-	blockingpicker    *pickerWrapper
+	// The following are initialized at dial time, and are read-only after that.
+	target          string               // User's dial target.
+	parsedTarget    resolver.Target      // See parseTargetAndFindResolver().
+	authority       string               // See determineAuthority().
+	dopts           dialOptions          // Default and user specified dial options.
+	channelzID      *channelz.Identifier // Channelz identifier for the channel.
+	balancerWrapper *ccBalancerWrapper   // Uses gracefulswitch.balancer underneath.
 
+	// The following provide their own synchronization, and therefore don't
+	// require cc.mu to be held to access them.
+	csMgr              *connectivityStateManager
+	blockingpicker     *pickerWrapper
 	safeConfigSelector iresolver.SafeConfigSelector
+	czData             *channelzData
+	retryThrottler     atomic.Value // Updated from service config.
 
-	mu              sync.RWMutex
-	resolverWrapper *ccResolverWrapper
-	sc              *ServiceConfig
-	conns           map[*addrConn]struct{}
-	// Keepalive parameter can be updated if a GoAway is received.
-	mkp             keepalive.ClientParameters
-	curBalancerName string
-	balancerWrapper *ccBalancerWrapper
-	retryThrottler  atomic.Value
-
+	// firstResolveEvent is used to track whether the name resolver sent us at
+	// least one update. RPCs block on this event.
 	firstResolveEvent *grpcsync.Event
 
-	channelzID int64 // channelz unique identification number
-	czData     *channelzData
+	// mu protects the following fields.
+	// TODO: split mu so the same mutex isn't used for everything.
+	mu              sync.RWMutex
+	resolverWrapper *ccResolverWrapper         // Initialized in Dial; cleared in Close.
+	sc              *ServiceConfig             // Latest service config received from the resolver.
+	conns           map[*addrConn]struct{}     // Set to nil on close.
+	mkp             keepalive.ClientParameters // May be updated upon receipt of a GoAway.
 
 	lceMu               sync.Mutex // protects lastConnectionError
 	lastConnectionError error
@@ -536,14 +535,7 @@ func (cc *ClientConn) GetState() connectivity.State {
 // Notice: This API is EXPERIMENTAL and may be changed or removed in a later
 // release.
 func (cc *ClientConn) Connect() {
-	cc.mu.Lock()
-	defer cc.mu.Unlock()
-	if cc.balancerWrapper != nil && cc.balancerWrapper.exitIdle() {
-		return
-	}
-	for ac := range cc.conns {
-		go ac.connect()
-	}
+	cc.balancerWrapper.exitIdle()
 }
 
 func (cc *ClientConn) scWatcher() {
@@ -623,9 +615,7 @@ func (cc *ClientConn) updateResolverState(s resolver.State, err error) error {
 		// with the new addresses.
 		cc.maybeApplyDefaultServiceConfig(nil)
 
-		if cc.balancerWrapper != nil {
-			cc.balancerWrapper.resolverError(err)
-		}
+		cc.balancerWrapper.resolverError(err)
 
 		// No addresses are valid with err set; return early.
 		cc.mu.Unlock()
@@ -653,16 +643,10 @@ func (cc *ClientConn) updateResolverState(s resolver.State, err error) error {
 			cc.applyServiceConfigAndBalancer(sc, configSelector, s.Addresses)
 		} else {
 			ret = balancer.ErrBadResolverState
-			if cc.balancerWrapper == nil {
-				var err error
-				if s.ServiceConfig.Err != nil {
-					err = status.Errorf(codes.Unavailable, "error parsing service config: %v", s.ServiceConfig.Err)
-				} else {
-					err = status.Errorf(codes.Unavailable, "illegal service config type: %T", s.ServiceConfig.Config)
-				}
-				cc.safeConfigSelector.UpdateConfigSelector(&defaultConfigSelector{cc.sc})
-				cc.blockingpicker.updatePicker(base.NewErrPicker(err))
-				cc.csMgr.updateState(connectivity.TransientFailure)
+			if cc.sc == nil {
+				// Apply the failing LB only if we haven't received valid service config
+				// from the name resolver in the past.
+				cc.applyFailingLB(s.ServiceConfig)
 				cc.mu.Unlock()
 				return ret
 			}
@@ -670,24 +654,12 @@ func (cc *ClientConn) updateResolverState(s resolver.State, err error) error {
 	}
 
 	var balCfg serviceconfig.LoadBalancingConfig
-	if cc.dopts.balancerBuilder == nil && cc.sc != nil && cc.sc.lbConfig != nil {
+	if cc.sc != nil && cc.sc.lbConfig != nil {
 		balCfg = cc.sc.lbConfig.cfg
 	}
-
-	cbn := cc.curBalancerName
 	bw := cc.balancerWrapper
 	cc.mu.Unlock()
-	if cbn != grpclbName {
-		// Filter any grpclb addresses since we don't have the grpclb balancer.
-		for i := 0; i < len(s.Addresses); {
-			if s.Addresses[i].Type == resolver.GRPCLB {
-				copy(s.Addresses[i:], s.Addresses[i+1:])
-				s.Addresses = s.Addresses[:len(s.Addresses)-1]
-				continue
-			}
-			i++
-		}
-	}
+
 	uccsErr := bw.updateClientConnState(&balancer.ClientConnState{ResolverState: s, BalancerConfig: balCfg})
 	if ret == nil {
 		ret = uccsErr // prefer ErrBadResolver state since any other error is
@@ -696,56 +668,28 @@ func (cc *ClientConn) updateResolverState(s resolver.State, err error) error {
 	return ret
 }
 
-// switchBalancer starts the switching from current balancer to the balancer
-// with the given name.
-//
-// It will NOT send the current address list to the new balancer. If needed,
-// caller of this function should send address list to the new balancer after
-// this function returns.
+// applyFailingLB is akin to configuring an LB policy on the channel which
+// always fails RPCs. Here, an actual LB policy is not configured, but an always
+// erroring picker is configured, which returns errors with information about
+// what was invalid in the received service config. A config selector with no
+// service config is configured, and the connectivity state of the channel is
+// set to TransientFailure.
 //
 // Caller must hold cc.mu.
-func (cc *ClientConn) switchBalancer(name string) {
-	if strings.EqualFold(cc.curBalancerName, name) {
-		return
-	}
-
-	channelz.Infof(logger, cc.channelzID, "ClientConn switching balancer to %q", name)
-	if cc.dopts.balancerBuilder != nil {
-		channelz.Info(logger, cc.channelzID, "ignoring balancer switching: Balancer DialOption used instead")
-		return
-	}
-	if cc.balancerWrapper != nil {
-		// Don't hold cc.mu while closing the balancers. The balancers may call
-		// methods that require cc.mu (e.g. cc.NewSubConn()). Holding the mutex
-		// would cause a deadlock in that case.
-		cc.mu.Unlock()
-		cc.balancerWrapper.close()
-		cc.mu.Lock()
-	}
-
-	builder := balancer.Get(name)
-	if builder == nil {
-		channelz.Warningf(logger, cc.channelzID, "Channel switches to new LB policy %q due to fallback from invalid balancer name", PickFirstBalancerName)
-		channelz.Infof(logger, cc.channelzID, "failed to get balancer builder for: %v, using pick_first instead", name)
-		builder = newPickfirstBuilder()
+func (cc *ClientConn) applyFailingLB(sc *serviceconfig.ParseResult) {
+	var err error
+	if sc.Err != nil {
+		err = status.Errorf(codes.Unavailable, "error parsing service config: %v", sc.Err)
 	} else {
-		channelz.Infof(logger, cc.channelzID, "Channel switches to new LB policy %q", name)
+		err = status.Errorf(codes.Unavailable, "illegal service config type: %T", sc.Config)
 	}
-
-	cc.curBalancerName = builder.Name()
-	cc.balancerWrapper = newCCBalancerWrapper(cc, builder, cc.balancerBuildOpts)
+	cc.safeConfigSelector.UpdateConfigSelector(&defaultConfigSelector{nil})
+	cc.blockingpicker.updatePicker(base.NewErrPicker(err))
+	cc.csMgr.updateState(connectivity.TransientFailure)
 }
 
 func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State, err error) {
-	cc.mu.Lock()
-	if cc.conns == nil {
-		cc.mu.Unlock()
-		return
-	}
-	// TODO(bar switching) send updates to all balancer wrappers when balancer
-	// gracefully switching is supported.
-	cc.balancerWrapper.handleSubConnStateChange(sc, s, err)
-	cc.mu.Unlock()
+	cc.balancerWrapper.updateSubConnState(sc, s, err)
 }
 
 // newAddrConn creates an addrConn for addrs and adds it to cc.conns.
@@ -768,17 +712,21 @@ func (cc *ClientConn) newAddrConn(addrs []resolver.Address, opts balancer.NewSub
 		cc.mu.Unlock()
 		return nil, ErrClientConnClosing
 	}
-	if channelz.IsOn() {
-		ac.channelzID = channelz.RegisterSubChannel(ac, cc.channelzID, "")
-		channelz.AddTraceEvent(logger, ac.channelzID, 0, &channelz.TraceEventDesc{
-			Desc:     "Subchannel Created",
-			Severity: channelz.CtInfo,
-			Parent: &channelz.TraceEventDesc{
-				Desc:     fmt.Sprintf("Subchannel(id:%d) created", ac.channelzID),
-				Severity: channelz.CtInfo,
-			},
-		})
+
+	var err error
+	ac.channelzID, err = channelz.RegisterSubChannel(ac, cc.channelzID, "")
+	if err != nil {
+		return nil, err
 	}
+	channelz.AddTraceEvent(logger, ac.channelzID, 0, &channelz.TraceEventDesc{
+		Desc:     "Subchannel created",
+		Severity: channelz.CtInfo,
+		Parent: &channelz.TraceEventDesc{
+			Desc:     fmt.Sprintf("Subchannel(id:%d) created", ac.channelzID.Int()),
+			Severity: channelz.CtInfo,
+		},
+	})
+
 	cc.conns[ac] = struct{}{}
 	cc.mu.Unlock()
 	return ac, nil
@@ -853,16 +801,31 @@ func (ac *addrConn) connect() error {
 	return nil
 }
 
+func equalAddresses(a, b []resolver.Address) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i, v := range a {
+		if !v.Equal(b[i]) {
+			return false
+		}
+	}
+	return true
+}
+
 // tryUpdateAddrs tries to update ac.addrs with the new addresses list.
 //
-// If ac is Connecting, it returns false. The caller should tear down the ac and
-// create a new one. Note that the backoff will be reset when this happens.
-//
 // If ac is TransientFailure, it updates ac.addrs and returns true. The updated
 // addresses will be picked up by retry in the next iteration after backoff.
 //
 // If ac is Shutdown or Idle, it updates ac.addrs and returns true.
 //
+// If the addresses is the same as the old list, it does nothing and returns
+// true.
+//
+// If ac is Connecting, it returns false. The caller should tear down the ac and
+// create a new one. Note that the backoff will be reset when this happens.
+//
 // If ac is Ready, it checks whether current connected address of ac is in the
 // new addrs list.
 //  - If true, it updates ac.addrs and returns true. The ac will keep using
@@ -879,6 +842,10 @@ func (ac *addrConn) tryUpdateAddrs(addrs []resolver.Address) bool {
 		return true
 	}
 
+	if equalAddresses(ac.addrs, addrs) {
+		return true
+	}
+
 	if ac.state == connectivity.Connecting {
 		return false
 	}
@@ -959,14 +926,10 @@ func (cc *ClientConn) healthCheckConfig() *healthCheckConfig {
 }
 
 func (cc *ClientConn) getTransport(ctx context.Context, failfast bool, method string) (transport.ClientTransport, func(balancer.DoneInfo), error) {
-	t, done, err := cc.blockingpicker.pick(ctx, failfast, balancer.PickInfo{
+	return cc.blockingpicker.pick(ctx, failfast, balancer.PickInfo{
 		Ctx:            ctx,
 		FullMethodName: method,
 	})
-	if err != nil {
-		return nil, nil, toRPCErr(err)
-	}
-	return t, done, nil
 }
 
 func (cc *ClientConn) applyServiceConfigAndBalancer(sc *ServiceConfig, configSelector iresolver.ConfigSelector, addrs []resolver.Address) {
@@ -991,35 +954,26 @@ func (cc *ClientConn) applyServiceConfigAndBalancer(sc *ServiceConfig, configSel
 		cc.retryThrottler.Store((*retryThrottler)(nil))
 	}
 
-	if cc.dopts.balancerBuilder == nil {
-		// Only look at balancer types and switch balancer if balancer dial
-		// option is not set.
-		var newBalancerName string
-		if cc.sc != nil && cc.sc.lbConfig != nil {
-			newBalancerName = cc.sc.lbConfig.name
-		} else {
-			var isGRPCLB bool
-			for _, a := range addrs {
-				if a.Type == resolver.GRPCLB {
-					isGRPCLB = true
-					break
-				}
-			}
-			if isGRPCLB {
-				newBalancerName = grpclbName
-			} else if cc.sc != nil && cc.sc.LB != nil {
-				newBalancerName = *cc.sc.LB
-			} else {
-				newBalancerName = PickFirstBalancerName
+	var newBalancerName string
+	if cc.sc != nil && cc.sc.lbConfig != nil {
+		newBalancerName = cc.sc.lbConfig.name
+	} else {
+		var isGRPCLB bool
+		for _, a := range addrs {
+			if a.Type == resolver.GRPCLB {
+				isGRPCLB = true
+				break
 			}
 		}
-		cc.switchBalancer(newBalancerName)
-	} else if cc.balancerWrapper == nil {
-		// Balancer dial option was set, and this is the first time handling
-		// resolved addresses. Build a balancer with dopts.balancerBuilder.
-		cc.curBalancerName = cc.dopts.balancerBuilder.Name()
-		cc.balancerWrapper = newCCBalancerWrapper(cc, cc.dopts.balancerBuilder, cc.balancerBuildOpts)
+		if isGRPCLB {
+			newBalancerName = grpclbName
+		} else if cc.sc != nil && cc.sc.LB != nil {
+			newBalancerName = *cc.sc.LB
+		} else {
+			newBalancerName = PickFirstBalancerName
+		}
 	}
+	cc.balancerWrapper.switchTo(newBalancerName)
 }
 
 func (cc *ClientConn) resolveNow(o resolver.ResolveNowOptions) {
@@ -1070,11 +1024,11 @@ func (cc *ClientConn) Close() error {
 	rWrapper := cc.resolverWrapper
 	cc.resolverWrapper = nil
 	bWrapper := cc.balancerWrapper
-	cc.balancerWrapper = nil
 	cc.mu.Unlock()
 
+	// The order of closing matters here since the balancer wrapper assumes the
+	// picker is closed before it is closed.
 	cc.blockingpicker.close()
-
 	if bWrapper != nil {
 		bWrapper.close()
 	}
@@ -1085,22 +1039,22 @@ func (cc *ClientConn) Close() error {
 	for ac := range conns {
 		ac.tearDown(ErrClientConnClosing)
 	}
-	if channelz.IsOn() {
-		ted := &channelz.TraceEventDesc{
-			Desc:     "Channel Deleted",
+	ted := &channelz.TraceEventDesc{
+		Desc:     "Channel deleted",
+		Severity: channelz.CtInfo,
+	}
+	if cc.dopts.channelzParentID != nil {
+		ted.Parent = &channelz.TraceEventDesc{
+			Desc:     fmt.Sprintf("Nested channel(id:%d) deleted", cc.channelzID.Int()),
 			Severity: channelz.CtInfo,
 		}
-		if cc.dopts.channelzParentID != 0 {
-			ted.Parent = &channelz.TraceEventDesc{
-				Desc:     fmt.Sprintf("Nested channel(id:%d) deleted", cc.channelzID),
-				Severity: channelz.CtInfo,
-			}
-		}
-		channelz.AddTraceEvent(logger, cc.channelzID, 0, ted)
-		// TraceEvent needs to be called before RemoveEntry, as TraceEvent may add trace reference to
-		// the entity being deleted, and thus prevent it from being deleted right away.
-		channelz.RemoveEntry(cc.channelzID)
 	}
+	channelz.AddTraceEvent(logger, cc.channelzID, 0, ted)
+	// TraceEvent needs to be called before RemoveEntry, as TraceEvent may add
+	// trace reference to the entity being deleted, and thus prevent it from being
+	// deleted right away.
+	channelz.RemoveEntry(cc.channelzID)
+
 	return nil
 }
 
@@ -1130,7 +1084,7 @@ type addrConn struct {
 	backoffIdx   int // Needs to be stateful for resetConnectBackoff.
 	resetBackoff chan struct{}
 
-	channelzID int64 // channelz unique identification number.
+	channelzID *channelz.Identifier
 	czData     *channelzData
 }
 
@@ -1284,6 +1238,7 @@ func (ac *addrConn) createTransport(addr resolver.Address, copts transport.Conne
 		ac.mu.Lock()
 		defer ac.mu.Unlock()
 		defer connClosed.Fire()
+		defer hcancel()
 		if !hcStarted || hctx.Err() != nil {
 			// We didn't start the health check or set the state to READY, so
 			// no need to do anything else here.
@@ -1294,7 +1249,6 @@ func (ac *addrConn) createTransport(addr resolver.Address, copts transport.Conne
 			// state, since there may be a new transport in this addrConn.
 			return
 		}
-		hcancel()
 		ac.transport = nil
 		// Refresh the name resolver
 		ac.cc.resolveNow(resolver.ResolveNowOptions{})
@@ -1312,14 +1266,13 @@ func (ac *addrConn) createTransport(addr resolver.Address, copts transport.Conne
 
 	connectCtx, cancel := context.WithDeadline(ac.ctx, connectDeadline)
 	defer cancel()
-	if channelz.IsOn() {
-		copts.ChannelzParentID = ac.channelzID
-	}
+	copts.ChannelzParentID = ac.channelzID
 
 	newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, addr, copts, func() { prefaceReceived.Fire() }, onGoAway, onClose)
 	if err != nil {
 		// newTr is either nil, or closed.
-		channelz.Warningf(logger, ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v. Err: %v", addr, err)
+		hcancel()
+		channelz.Warningf(logger, ac.channelzID, "grpc: addrConn.createTransport failed to connect to %s. Err: %v", addr, err)
 		return err
 	}
 
@@ -1332,7 +1285,7 @@ func (ac *addrConn) createTransport(addr resolver.Address, copts transport.Conne
 		newTr.Close(transport.ErrConnClosing)
 		if connectCtx.Err() == context.DeadlineExceeded {
 			err := errors.New("failed to receive server preface within timeout")
-			channelz.Warningf(logger, ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v: %v", addr, err)
+			channelz.Warningf(logger, ac.channelzID, "grpc: addrConn.createTransport failed to connect to %s: %v", addr, err)
 			return err
 		}
 		return nil
@@ -1497,19 +1450,18 @@ func (ac *addrConn) tearDown(err error) {
 		curTr.GracefulClose()
 		ac.mu.Lock()
 	}
-	if channelz.IsOn() {
-		channelz.AddTraceEvent(logger, ac.channelzID, 0, &channelz.TraceEventDesc{
-			Desc:     "Subchannel Deleted",
+	channelz.AddTraceEvent(logger, ac.channelzID, 0, &channelz.TraceEventDesc{
+		Desc:     "Subchannel deleted",
+		Severity: channelz.CtInfo,
+		Parent: &channelz.TraceEventDesc{
+			Desc:     fmt.Sprintf("Subchannel(id:%d) deleted", ac.channelzID.Int()),
 			Severity: channelz.CtInfo,
-			Parent: &channelz.TraceEventDesc{
-				Desc:     fmt.Sprintf("Subchanel(id:%d) deleted", ac.channelzID),
-				Severity: channelz.CtInfo,
-			},
-		})
-		// TraceEvent needs to be called before RemoveEntry, as TraceEvent may add trace reference to
-		// the entity being deleted, and thus prevent it from being deleted right away.
-		channelz.RemoveEntry(ac.channelzID)
-	}
+		},
+	})
+	// TraceEvent needs to be called before RemoveEntry, as TraceEvent may add
+	// trace reference to the entity being deleted, and thus prevent it from
+	// being deleted right away.
+	channelz.RemoveEntry(ac.channelzID)
 	ac.mu.Unlock()
 }
 

vendor/google.golang.org/grpc/dialoptions.go

@@ -20,12 +20,11 @@ package grpc
 
 import (
 	"context"
-	"fmt"
 	"net"
 	"time"
 
 	"google.golang.org/grpc/backoff"
-	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/channelz"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/internal"
@@ -45,19 +44,17 @@ type dialOptions struct {
 	chainUnaryInts  []UnaryClientInterceptor
 	chainStreamInts []StreamClientInterceptor
 
-	cp              Compressor
-	dc              Decompressor
-	bs              internalbackoff.Strategy
-	block           bool
-	returnLastError bool
-	timeout         time.Duration
-	scChan          <-chan ServiceConfig
-	authority       string
-	copts           transport.ConnectOptions
-	callOptions     []CallOption
-	// This is used by WithBalancerName dial option.
-	balancerBuilder             balancer.Builder
-	channelzParentID            int64
+	cp                          Compressor
+	dc                          Decompressor
+	bs                          internalbackoff.Strategy
+	block                       bool
+	returnLastError             bool
+	timeout                     time.Duration
+	scChan                      <-chan ServiceConfig
+	authority                   string
+	copts                       transport.ConnectOptions
+	callOptions                 []CallOption
+	channelzParentID            *channelz.Identifier
 	disableServiceConfig        bool
 	disableRetry                bool
 	disableHealthCheck          bool
@@ -195,25 +192,6 @@ func WithDecompressor(dc Decompressor) DialOption {
 	})
 }
 
-// WithBalancerName sets the balancer that the ClientConn will be initialized
-// with. Balancer registered with balancerName will be used. This function
-// panics if no balancer was registered by balancerName.
-//
-// The balancer cannot be overridden by balancer option specified by service
-// config.
-//
-// Deprecated: use WithDefaultServiceConfig and WithDisableServiceConfig
-// instead.  Will be removed in a future 1.x release.
-func WithBalancerName(balancerName string) DialOption {
-	builder := balancer.Get(balancerName)
-	if builder == nil {
-		panic(fmt.Sprintf("grpc.WithBalancerName: no balancer is registered for name %v", balancerName))
-	}
-	return newFuncDialOption(func(o *dialOptions) {
-		o.balancerBuilder = builder
-	})
-}
-
 // WithServiceConfig returns a DialOption which has a channel to read the
 // service configuration.
 //
@@ -304,8 +282,8 @@ func WithReturnConnectionError() DialOption {
 // WithCredentialsBundle or WithPerRPCCredentials) which require transport
 // security is incompatible and will cause grpc.Dial() to fail.
 //
-// Deprecated: use WithTransportCredentials and insecure.NewCredentials() instead.
-// Will be supported throughout 1.x.
+// Deprecated: use WithTransportCredentials and insecure.NewCredentials()
+// instead. Will be supported throughout 1.x.
 func WithInsecure() DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		o.copts.TransportCredentials = insecure.NewCredentials()
@@ -498,7 +476,7 @@ func WithAuthority(a string) DialOption {
 //
 // Notice: This API is EXPERIMENTAL and may be changed or removed in a
 // later release.
-func WithChannelzParentID(id int64) DialOption {
+func WithChannelzParentID(id *channelz.Identifier) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		o.channelzParentID = id
 	})

vendor/google.golang.org/grpc/encoding/encoding.go

@@ -108,7 +108,7 @@ var registeredCodecs = make(map[string]Codec)
 // more details.
 //
 // NOTE: this function must only be called during initialization time (i.e. in
-// an init() function), and is not thread-safe.  If multiple Compressors are
+// an init() function), and is not thread-safe.  If multiple Codecs are
 // registered with the same name, the one registered last will take effect.
 func RegisterCodec(codec Codec) {
 	if codec == nil {

vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/gracefulswitch.go

@@ -0,0 +1,382 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package gracefulswitch implements a graceful switch load balancer.
+package gracefulswitch
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/resolver"
+)
+
+var errBalancerClosed = errors.New("gracefulSwitchBalancer is closed")
+var _ balancer.Balancer = (*Balancer)(nil)
+
+// NewBalancer returns a graceful switch Balancer.
+func NewBalancer(cc balancer.ClientConn, opts balancer.BuildOptions) *Balancer {
+	return &Balancer{
+		cc:    cc,
+		bOpts: opts,
+	}
+}
+
+// Balancer is a utility to gracefully switch from one balancer to
+// a new balancer. It implements the balancer.Balancer interface.
+type Balancer struct {
+	bOpts balancer.BuildOptions
+	cc    balancer.ClientConn
+
+	// mu protects the following fields and all fields within balancerCurrent
+	// and balancerPending. mu does not need to be held when calling into the
+	// child balancers, as all calls into these children happen only as a direct
+	// result of a call into the gracefulSwitchBalancer, which are also
+	// guaranteed to be synchronous. There is one exception: an UpdateState call
+	// from a child balancer when current and pending are populated can lead to
+	// calling Close() on the current. To prevent that racing with an
+	// UpdateSubConnState from the channel, we hold currentMu during Close and
+	// UpdateSubConnState calls.
+	mu              sync.Mutex
+	balancerCurrent *balancerWrapper
+	balancerPending *balancerWrapper
+	closed          bool // set to true when this balancer is closed
+
+	// currentMu must be locked before mu. This mutex guards against this
+	// sequence of events: UpdateSubConnState() called, finds the
+	// balancerCurrent, gives up lock, updateState comes in, causes Close() on
+	// balancerCurrent before the UpdateSubConnState is called on the
+	// balancerCurrent.
+	currentMu sync.Mutex
+}
+
+// swap swaps out the current lb with the pending lb and updates the ClientConn.
+// The caller must hold gsb.mu.
+func (gsb *Balancer) swap() {
+	gsb.cc.UpdateState(gsb.balancerPending.lastState)
+	cur := gsb.balancerCurrent
+	gsb.balancerCurrent = gsb.balancerPending
+	gsb.balancerPending = nil
+	go func() {
+		gsb.currentMu.Lock()
+		defer gsb.currentMu.Unlock()
+		cur.Close()
+	}()
+}
+
+// Helper function that checks if the balancer passed in is current or pending.
+// The caller must hold gsb.mu.
+func (gsb *Balancer) balancerCurrentOrPending(bw *balancerWrapper) bool {
+	return bw == gsb.balancerCurrent || bw == gsb.balancerPending
+}
+
+// SwitchTo initializes the graceful switch process, which completes based on
+// connectivity state changes on the current/pending balancer. Thus, the switch
+// process is not complete when this method returns. This method must be called
+// synchronously alongside the rest of the balancer.Balancer methods this
+// Graceful Switch Balancer implements.
+func (gsb *Balancer) SwitchTo(builder balancer.Builder) error {
+	gsb.mu.Lock()
+	if gsb.closed {
+		gsb.mu.Unlock()
+		return errBalancerClosed
+	}
+	bw := &balancerWrapper{
+		gsb: gsb,
+		lastState: balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            base.NewErrPicker(balancer.ErrNoSubConnAvailable),
+		},
+		subconns: make(map[balancer.SubConn]bool),
+	}
+	balToClose := gsb.balancerPending // nil if there is no pending balancer
+	if gsb.balancerCurrent == nil {
+		gsb.balancerCurrent = bw
+	} else {
+		gsb.balancerPending = bw
+	}
+	gsb.mu.Unlock()
+	balToClose.Close()
+	// This function takes a builder instead of a balancer because builder.Build
+	// can call back inline, and this utility needs to handle the callbacks.
+	newBalancer := builder.Build(bw, gsb.bOpts)
+	if newBalancer == nil {
+		// This is illegal and should never happen; we clear the balancerWrapper
+		// we were constructing if it happens to avoid a potential panic.
+		gsb.mu.Lock()
+		if gsb.balancerPending != nil {
+			gsb.balancerPending = nil
+		} else {
+			gsb.balancerCurrent = nil
+		}
+		gsb.mu.Unlock()
+		return balancer.ErrBadResolverState
+	}
+
+	// This write doesn't need to take gsb.mu because this field never gets read
+	// or written to on any calls from the current or pending. Calls from grpc
+	// to this balancer are guaranteed to be called synchronously, so this
+	// bw.Balancer field will never be forwarded to until this SwitchTo()
+	// function returns.
+	bw.Balancer = newBalancer
+	return nil
+}
+
+// Returns nil if the graceful switch balancer is closed.
+func (gsb *Balancer) latestBalancer() *balancerWrapper {
+	gsb.mu.Lock()
+	defer gsb.mu.Unlock()
+	if gsb.balancerPending != nil {
+		return gsb.balancerPending
+	}
+	return gsb.balancerCurrent
+}
+
+// UpdateClientConnState forwards the update to the latest balancer created.
+func (gsb *Balancer) UpdateClientConnState(state balancer.ClientConnState) error {
+	// The resolver data is only relevant to the most recent LB Policy.
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return errBalancerClosed
+	}
+	// Perform this call without gsb.mu to prevent deadlocks if the child calls
+	// back into the channel. The latest balancer can never be closed during a
+	// call from the channel, even without gsb.mu held.
+	return balToUpdate.UpdateClientConnState(state)
+}
+
+// ResolverError forwards the error to the latest balancer created.
+func (gsb *Balancer) ResolverError(err error) {
+	// The resolver data is only relevant to the most recent LB Policy.
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return
+	}
+	// Perform this call without gsb.mu to prevent deadlocks if the child calls
+	// back into the channel. The latest balancer can never be closed during a
+	// call from the channel, even without gsb.mu held.
+	balToUpdate.ResolverError(err)
+}
+
+// ExitIdle forwards the call to the latest balancer created.
+//
+// If the latest balancer does not support ExitIdle, the subConns are
+// re-connected to manually.
+func (gsb *Balancer) ExitIdle() {
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return
+	}
+	// There is no need to protect this read with a mutex, as the write to the
+	// Balancer field happens in SwitchTo, which completes before this can be
+	// called.
+	if ei, ok := balToUpdate.Balancer.(balancer.ExitIdler); ok {
+		ei.ExitIdle()
+		return
+	}
+	for sc := range balToUpdate.subconns {
+		sc.Connect()
+	}
+}
+
+// UpdateSubConnState forwards the update to the appropriate child.
+func (gsb *Balancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	gsb.currentMu.Lock()
+	defer gsb.currentMu.Unlock()
+	gsb.mu.Lock()
+	// Forward update to the appropriate child.  Even if there is a pending
+	// balancer, the current balancer should continue to get SubConn updates to
+	// maintain the proper state while the pending is still connecting.
+	var balToUpdate *balancerWrapper
+	if gsb.balancerCurrent != nil && gsb.balancerCurrent.subconns[sc] {
+		balToUpdate = gsb.balancerCurrent
+	} else if gsb.balancerPending != nil && gsb.balancerPending.subconns[sc] {
+		balToUpdate = gsb.balancerPending
+	}
+	gsb.mu.Unlock()
+	if balToUpdate == nil {
+		// SubConn belonged to a stale lb policy that has not yet fully closed,
+		// or the balancer was already closed.
+		return
+	}
+	balToUpdate.UpdateSubConnState(sc, state)
+}
+
+// Close closes any active child balancers.
+func (gsb *Balancer) Close() {
+	gsb.mu.Lock()
+	gsb.closed = true
+	currentBalancerToClose := gsb.balancerCurrent
+	gsb.balancerCurrent = nil
+	pendingBalancerToClose := gsb.balancerPending
+	gsb.balancerPending = nil
+	gsb.mu.Unlock()
+
+	currentBalancerToClose.Close()
+	pendingBalancerToClose.Close()
+}
+
+// balancerWrapper wraps a balancer.Balancer, and overrides some Balancer
+// methods to help cleanup SubConns created by the wrapped balancer.
+//
+// It implements the balancer.ClientConn interface and is passed down in that
+// capacity to the wrapped balancer. It maintains a set of subConns created by
+// the wrapped balancer and calls from the latter to create/update/remove
+// SubConns update this set before being forwarded to the parent ClientConn.
+// State updates from the wrapped balancer can result in invocation of the
+// graceful switch logic.
+type balancerWrapper struct {
+	balancer.Balancer
+	gsb *Balancer
+
+	lastState balancer.State
+	subconns  map[balancer.SubConn]bool // subconns created by this balancer
+}
+
+func (bw *balancerWrapper) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	if state.ConnectivityState == connectivity.Shutdown {
+		bw.gsb.mu.Lock()
+		delete(bw.subconns, sc)
+		bw.gsb.mu.Unlock()
+	}
+	// There is no need to protect this read with a mutex, as the write to the
+	// Balancer field happens in SwitchTo, which completes before this can be
+	// called.
+	bw.Balancer.UpdateSubConnState(sc, state)
+}
+
+// Close closes the underlying LB policy and removes the subconns it created. bw
+// must not be referenced via balancerCurrent or balancerPending in gsb when
+// called. gsb.mu must not be held.  Does not panic with a nil receiver.
+func (bw *balancerWrapper) Close() {
+	// before Close is called.
+	if bw == nil {
+		return
+	}
+	// There is no need to protect this read with a mutex, as Close() is
+	// impossible to be called concurrently with the write in SwitchTo(). The
+	// callsites of Close() for this balancer in Graceful Switch Balancer will
+	// never be called until SwitchTo() returns.
+	bw.Balancer.Close()
+	bw.gsb.mu.Lock()
+	for sc := range bw.subconns {
+		bw.gsb.cc.RemoveSubConn(sc)
+	}
+	bw.gsb.mu.Unlock()
+}
+
+func (bw *balancerWrapper) UpdateState(state balancer.State) {
+	// Hold the mutex for this entire call to ensure it cannot occur
+	// concurrently with other updateState() calls. This causes updates to
+	// lastState and calls to cc.UpdateState to happen atomically.
+	bw.gsb.mu.Lock()
+	defer bw.gsb.mu.Unlock()
+	bw.lastState = state
+
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		return
+	}
+
+	if bw == bw.gsb.balancerCurrent {
+		// In the case that the current balancer exits READY, and there is a pending
+		// balancer, you can forward the pending balancer's cached State up to
+		// ClientConn and swap the pending into the current. This is because there
+		// is no reason to gracefully switch from and keep using the old policy as
+		// the ClientConn is not connected to any backends.
+		if state.ConnectivityState != connectivity.Ready && bw.gsb.balancerPending != nil {
+			bw.gsb.swap()
+			return
+		}
+		// Even if there is a pending balancer waiting to be gracefully switched to,
+		// continue to forward current balancer updates to the Client Conn. Ignoring
+		// state + picker from the current would cause undefined behavior/cause the
+		// system to behave incorrectly from the current LB policies perspective.
+		// Also, the current LB is still being used by grpc to choose SubConns per
+		// RPC, and thus should use the most updated form of the current balancer.
+		bw.gsb.cc.UpdateState(state)
+		return
+	}
+	// This method is now dealing with a state update from the pending balancer.
+	// If the current balancer is currently in a state other than READY, the new
+	// policy can be swapped into place immediately. This is because there is no
+	// reason to gracefully switch from and keep using the old policy as the
+	// ClientConn is not connected to any backends.
+	if state.ConnectivityState != connectivity.Connecting || bw.gsb.balancerCurrent.lastState.ConnectivityState != connectivity.Ready {
+		bw.gsb.swap()
+	}
+}
+
+func (bw *balancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
+	}
+	bw.gsb.mu.Unlock()
+
+	sc, err := bw.gsb.cc.NewSubConn(addrs, opts)
+	if err != nil {
+		return nil, err
+	}
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) { // balancer was closed during this call
+		bw.gsb.cc.RemoveSubConn(sc)
+		bw.gsb.mu.Unlock()
+		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
+	}
+	bw.subconns[sc] = true
+	bw.gsb.mu.Unlock()
+	return sc, nil
+}
+
+func (bw *balancerWrapper) ResolveNow(opts resolver.ResolveNowOptions) {
+	// Ignore ResolveNow requests from anything other than the most recent
+	// balancer, because older balancers were already removed from the config.
+	if bw != bw.gsb.latestBalancer() {
+		return
+	}
+	bw.gsb.cc.ResolveNow(opts)
+}
+
+func (bw *balancerWrapper) RemoveSubConn(sc balancer.SubConn) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return
+	}
+	bw.gsb.mu.Unlock()
+	bw.gsb.cc.RemoveSubConn(sc)
+}
+
+func (bw *balancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver.Address) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return
+	}
+	bw.gsb.mu.Unlock()
+	bw.gsb.cc.UpdateAddresses(sc, addrs)
+}
+
+func (bw *balancerWrapper) Target() string {
+	return bw.gsb.cc.Target()
+}

vendor/google.golang.org/grpc/internal/binarylog/binarylog.go

@@ -31,7 +31,7 @@ import (
 // Logger is the global binary logger. It can be used to get binary logger for
 // each method.
 type Logger interface {
-	getMethodLogger(methodName string) *MethodLogger
+	GetMethodLogger(methodName string) MethodLogger
 }
 
 // binLogger is the global binary logger for the binary. One of this should be
@@ -49,17 +49,24 @@ func SetLogger(l Logger) {
 	binLogger = l
 }
 
+// GetLogger gets the binarg logger.
+//
+// Only call this at init time.
+func GetLogger() Logger {
+	return binLogger
+}
+
 // GetMethodLogger returns the methodLogger for the given methodName.
 //
 // methodName should be in the format of "/service/method".
 //
 // Each methodLogger returned by this method is a new instance. This is to
 // generate sequence id within the call.
-func GetMethodLogger(methodName string) *MethodLogger {
+func GetMethodLogger(methodName string) MethodLogger {
 	if binLogger == nil {
 		return nil
 	}
-	return binLogger.getMethodLogger(methodName)
+	return binLogger.GetMethodLogger(methodName)
 }
 
 func init() {
@@ -68,17 +75,29 @@ func init() {
 	binLogger = NewLoggerFromConfigString(configStr)
 }
 
-type methodLoggerConfig struct {
+// MethodLoggerConfig contains the setting for logging behavior of a method
+// logger. Currently, it contains the max length of header and message.
+type MethodLoggerConfig struct {
 	// Max length of header and message.
-	hdr, msg uint64
+	Header, Message uint64
+}
+
+// LoggerConfig contains the config for loggers to create method loggers.
+type LoggerConfig struct {
+	All      *MethodLoggerConfig
+	Services map[string]*MethodLoggerConfig
+	Methods  map[string]*MethodLoggerConfig
+
+	Blacklist map[string]struct{}
 }
 
 type logger struct {
-	all      *methodLoggerConfig
-	services map[string]*methodLoggerConfig
-	methods  map[string]*methodLoggerConfig
+	config LoggerConfig
+}
 
-	blacklist map[string]struct{}
+// NewLoggerFromConfig builds a logger with the given LoggerConfig.
+func NewLoggerFromConfig(config LoggerConfig) Logger {
+	return &logger{config: config}
 }
 
 // newEmptyLogger creates an empty logger. The map fields need to be filled in
@@ -88,57 +107,57 @@ func newEmptyLogger() *logger {
 }
 
 // Set method logger for "*".
-func (l *logger) setDefaultMethodLogger(ml *methodLoggerConfig) error {
-	if l.all != nil {
+func (l *logger) setDefaultMethodLogger(ml *MethodLoggerConfig) error {
+	if l.config.All != nil {
 		return fmt.Errorf("conflicting global rules found")
 	}
-	l.all = ml
+	l.config.All = ml
 	return nil
 }
 
 // Set method logger for "service/*".
 //
 // New methodLogger with same service overrides the old one.
-func (l *logger) setServiceMethodLogger(service string, ml *methodLoggerConfig) error {
-	if _, ok := l.services[service]; ok {
+func (l *logger) setServiceMethodLogger(service string, ml *MethodLoggerConfig) error {
+	if _, ok := l.config.Services[service]; ok {
 		return fmt.Errorf("conflicting service rules for service %v found", service)
 	}
-	if l.services == nil {
-		l.services = make(map[string]*methodLoggerConfig)
+	if l.config.Services == nil {
+		l.config.Services = make(map[string]*MethodLoggerConfig)
 	}
-	l.services[service] = ml
+	l.config.Services[service] = ml
 	return nil
 }
 
 // Set method logger for "service/method".
 //
 // New methodLogger with same method overrides the old one.
-func (l *logger) setMethodMethodLogger(method string, ml *methodLoggerConfig) error {
-	if _, ok := l.blacklist[method]; ok {
+func (l *logger) setMethodMethodLogger(method string, ml *MethodLoggerConfig) error {
+	if _, ok := l.config.Blacklist[method]; ok {
 		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
 	}
-	if _, ok := l.methods[method]; ok {
+	if _, ok := l.config.Methods[method]; ok {
 		return fmt.Errorf("conflicting method rules for method %v found", method)
 	}
-	if l.methods == nil {
-		l.methods = make(map[string]*methodLoggerConfig)
+	if l.config.Methods == nil {
+		l.config.Methods = make(map[string]*MethodLoggerConfig)
 	}
-	l.methods[method] = ml
+	l.config.Methods[method] = ml
 	return nil
 }
 
 // Set blacklist method for "-service/method".
 func (l *logger) setBlacklist(method string) error {
-	if _, ok := l.blacklist[method]; ok {
+	if _, ok := l.config.Blacklist[method]; ok {
 		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
 	}
-	if _, ok := l.methods[method]; ok {
+	if _, ok := l.config.Methods[method]; ok {
 		return fmt.Errorf("conflicting method rules for method %v found", method)
 	}
-	if l.blacklist == nil {
-		l.blacklist = make(map[string]struct{})
+	if l.config.Blacklist == nil {
+		l.config.Blacklist = make(map[string]struct{})
 	}
-	l.blacklist[method] = struct{}{}
+	l.config.Blacklist[method] = struct{}{}
 	return nil
 }
 
@@ -148,23 +167,23 @@ func (l *logger) setBlacklist(method string) error {
 //
 // Each methodLogger returned by this method is a new instance. This is to
 // generate sequence id within the call.
-func (l *logger) getMethodLogger(methodName string) *MethodLogger {
+func (l *logger) GetMethodLogger(methodName string) MethodLogger {
 	s, m, err := grpcutil.ParseMethod(methodName)
 	if err != nil {
 		grpclogLogger.Infof("binarylogging: failed to parse %q: %v", methodName, err)
 		return nil
 	}
-	if ml, ok := l.methods[s+"/"+m]; ok {
-		return newMethodLogger(ml.hdr, ml.msg)
+	if ml, ok := l.config.Methods[s+"/"+m]; ok {
+		return newMethodLogger(ml.Header, ml.Message)
 	}
-	if _, ok := l.blacklist[s+"/"+m]; ok {
+	if _, ok := l.config.Blacklist[s+"/"+m]; ok {
 		return nil
 	}
-	if ml, ok := l.services[s]; ok {
-		return newMethodLogger(ml.hdr, ml.msg)
+	if ml, ok := l.config.Services[s]; ok {
+		return newMethodLogger(ml.Header, ml.Message)
 	}
-	if l.all == nil {
+	if l.config.All == nil {
 		return nil
 	}
-	return newMethodLogger(l.all.hdr, l.all.msg)
+	return newMethodLogger(l.config.All.Header, l.config.All.Message)
 }

vendor/google.golang.org/grpc/internal/binarylog/env_config.go

@@ -89,7 +89,7 @@ func (l *logger) fillMethodLoggerWithConfigString(config string) error {
 		if err != nil {
 			return fmt.Errorf("invalid config: %q, %v", config, err)
 		}
-		if err := l.setDefaultMethodLogger(&methodLoggerConfig{hdr: hdr, msg: msg}); err != nil {
+		if err := l.setDefaultMethodLogger(&MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
 			return fmt.Errorf("invalid config: %v", err)
 		}
 		return nil
@@ -104,11 +104,11 @@ func (l *logger) fillMethodLoggerWithConfigString(config string) error {
 		return fmt.Errorf("invalid header/message length config: %q, %v", suffix, err)
 	}
 	if m == "*" {
-		if err := l.setServiceMethodLogger(s, &methodLoggerConfig{hdr: hdr, msg: msg}); err != nil {
+		if err := l.setServiceMethodLogger(s, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
 			return fmt.Errorf("invalid config: %v", err)
 		}
 	} else {
-		if err := l.setMethodMethodLogger(s+"/"+m, &methodLoggerConfig{hdr: hdr, msg: msg}); err != nil {
+		if err := l.setMethodMethodLogger(s+"/"+m, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
 			return fmt.Errorf("invalid config: %v", err)
 		}
 	}

vendor/google.golang.org/grpc/internal/binarylog/method_logger.go

@@ -48,7 +48,11 @@ func (g *callIDGenerator) reset() {
 var idGen callIDGenerator
 
 // MethodLogger is the sub-logger for each method.
-type MethodLogger struct {
+type MethodLogger interface {
+	Log(LogEntryConfig)
+}
+
+type methodLogger struct {
 	headerMaxLen, messageMaxLen uint64
 
 	callID          uint64
@@ -57,8 +61,8 @@ type MethodLogger struct {
 	sink Sink // TODO(blog): make this plugable.
 }
 
-func newMethodLogger(h, m uint64) *MethodLogger {
-	return &MethodLogger{
+func newMethodLogger(h, m uint64) *methodLogger {
+	return &methodLogger{
 		headerMaxLen:  h,
 		messageMaxLen: m,
 
@@ -69,8 +73,10 @@ func newMethodLogger(h, m uint64) *MethodLogger {
 	}
 }
 
-// Log creates a proto binary log entry, and logs it to the sink.
-func (ml *MethodLogger) Log(c LogEntryConfig) {
+// Build is an internal only method for building the proto message out of the
+// input event. It's made public to enable other library to reuse as much logic
+// in methodLogger as possible.
+func (ml *methodLogger) Build(c LogEntryConfig) *pb.GrpcLogEntry {
 	m := c.toProto()
 	timestamp, _ := ptypes.TimestampProto(time.Now())
 	m.Timestamp = timestamp
@@ -85,11 +91,15 @@ func (ml *MethodLogger) Log(c LogEntryConfig) {
 	case *pb.GrpcLogEntry_Message:
 		m.PayloadTruncated = ml.truncateMessage(pay.Message)
 	}
-
-	ml.sink.Write(m)
+	return m
 }
 
-func (ml *MethodLogger) truncateMetadata(mdPb *pb.Metadata) (truncated bool) {
+// Log creates a proto binary log entry, and logs it to the sink.
+func (ml *methodLogger) Log(c LogEntryConfig) {
+	ml.sink.Write(ml.Build(c))
+}
+
+func (ml *methodLogger) truncateMetadata(mdPb *pb.Metadata) (truncated bool) {
 	if ml.headerMaxLen == maxUInt {
 		return false
 	}
@@ -119,7 +129,7 @@ func (ml *MethodLogger) truncateMetadata(mdPb *pb.Metadata) (truncated bool) {
 	return truncated
 }
 
-func (ml *MethodLogger) truncateMessage(msgPb *pb.Message) (truncated bool) {
+func (ml *methodLogger) truncateMessage(msgPb *pb.Message) (truncated bool) {
 	if ml.messageMaxLen == maxUInt {
 		return false
 	}

vendor/google.golang.org/grpc/internal/channelz/funcs.go

@@ -25,6 +25,7 @@ package channelz
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"sort"
 	"sync"
@@ -184,54 +185,77 @@ func GetServer(id int64) *ServerMetric {
 	return db.get().GetServer(id)
 }
 
-// RegisterChannel registers the given channel c in channelz database with ref
-// as its reference name, and add it to the child list of its parent (identified
-// by pid). pid = 0 means no parent. It returns the unique channelz tracking id
-// assigned to this channel.
-func RegisterChannel(c Channel, pid int64, ref string) int64 {
+// RegisterChannel registers the given channel c in the channelz database with
+// ref as its reference name, and adds it to the child list of its parent
+// (identified by pid). pid == nil means no parent.
+//
+// Returns a unique channelz identifier assigned to this channel.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterChannel(c Channel, pid *Identifier, ref string) *Identifier {
 	id := idGen.genID()
+	var parent int64
+	isTopChannel := true
+	if pid != nil {
+		isTopChannel = false
+		parent = pid.Int()
+	}
+
+	if !IsOn() {
+		return newIdentifer(RefChannel, id, pid)
+	}
+
 	cn := &channel{
 		refName:     ref,
 		c:           c,
 		subChans:    make(map[int64]string),
 		nestedChans: make(map[int64]string),
 		id:          id,
-		pid:         pid,
+		pid:         parent,
 		trace:       &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
 	}
-	if pid == 0 {
-		db.get().addChannel(id, cn, true, pid)
-	} else {
-		db.get().addChannel(id, cn, false, pid)
-	}
-	return id
+	db.get().addChannel(id, cn, isTopChannel, parent)
+	return newIdentifer(RefChannel, id, pid)
 }
 
-// RegisterSubChannel registers the given channel c in channelz database with ref
-// as its reference name, and add it to the child list of its parent (identified
-// by pid). It returns the unique channelz tracking id assigned to this subchannel.
-func RegisterSubChannel(c Channel, pid int64, ref string) int64 {
-	if pid == 0 {
-		logger.Error("a SubChannel's parent id cannot be 0")
-		return 0
+// RegisterSubChannel registers the given subChannel c in the channelz database
+// with ref as its reference name, and adds it to the child list of its parent
+// (identified by pid).
+//
+// Returns a unique channelz identifier assigned to this subChannel.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterSubChannel(c Channel, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a SubChannel's parent id cannot be nil")
 	}
 	id := idGen.genID()
+	if !IsOn() {
+		return newIdentifer(RefSubChannel, id, pid), nil
+	}
+
 	sc := &subChannel{
 		refName: ref,
 		c:       c,
 		sockets: make(map[int64]string),
 		id:      id,
-		pid:     pid,
+		pid:     pid.Int(),
 		trace:   &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
 	}
-	db.get().addSubChannel(id, sc, pid)
-	return id
+	db.get().addSubChannel(id, sc, pid.Int())
+	return newIdentifer(RefSubChannel, id, pid), nil
 }
 
 // RegisterServer registers the given server s in channelz database. It returns
 // the unique channelz tracking id assigned to this server.
-func RegisterServer(s Server, ref string) int64 {
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterServer(s Server, ref string) *Identifier {
 	id := idGen.genID()
+	if !IsOn() {
+		return newIdentifer(RefServer, id, nil)
+	}
+
 	svr := &server{
 		refName:       ref,
 		s:             s,
@@ -240,71 +264,92 @@ func RegisterServer(s Server, ref string) int64 {
 		id:            id,
 	}
 	db.get().addServer(id, svr)
-	return id
+	return newIdentifer(RefServer, id, nil)
 }
 
 // RegisterListenSocket registers the given listen socket s in channelz database
 // with ref as its reference name, and add it to the child list of its parent
 // (identified by pid). It returns the unique channelz tracking id assigned to
 // this listen socket.
-func RegisterListenSocket(s Socket, pid int64, ref string) int64 {
-	if pid == 0 {
-		logger.Error("a ListenSocket's parent id cannot be 0")
-		return 0
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterListenSocket(s Socket, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a ListenSocket's parent id cannot be 0")
 	}
 	id := idGen.genID()
-	ls := &listenSocket{refName: ref, s: s, id: id, pid: pid}
-	db.get().addListenSocket(id, ls, pid)
-	return id
+	if !IsOn() {
+		return newIdentifer(RefListenSocket, id, pid), nil
+	}
+
+	ls := &listenSocket{refName: ref, s: s, id: id, pid: pid.Int()}
+	db.get().addListenSocket(id, ls, pid.Int())
+	return newIdentifer(RefListenSocket, id, pid), nil
 }
 
 // RegisterNormalSocket registers the given normal socket s in channelz database
-// with ref as its reference name, and add it to the child list of its parent
+// with ref as its reference name, and adds it to the child list of its parent
 // (identified by pid). It returns the unique channelz tracking id assigned to
 // this normal socket.
-func RegisterNormalSocket(s Socket, pid int64, ref string) int64 {
-	if pid == 0 {
-		logger.Error("a NormalSocket's parent id cannot be 0")
-		return 0
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterNormalSocket(s Socket, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a NormalSocket's parent id cannot be 0")
 	}
 	id := idGen.genID()
-	ns := &normalSocket{refName: ref, s: s, id: id, pid: pid}
-	db.get().addNormalSocket(id, ns, pid)
-	return id
+	if !IsOn() {
+		return newIdentifer(RefNormalSocket, id, pid), nil
+	}
+
+	ns := &normalSocket{refName: ref, s: s, id: id, pid: pid.Int()}
+	db.get().addNormalSocket(id, ns, pid.Int())
+	return newIdentifer(RefNormalSocket, id, pid), nil
 }
 
 // RemoveEntry removes an entry with unique channelz tracking id to be id from
 // channelz database.
-func RemoveEntry(id int64) {
-	db.get().removeEntry(id)
+//
+// If channelz is not turned ON, this function is a no-op.
+func RemoveEntry(id *Identifier) {
+	if !IsOn() {
+		return
+	}
+	db.get().removeEntry(id.Int())
 }
 
-// TraceEventDesc is what the caller of AddTraceEvent should provide to describe the event to be added
-// to the channel trace.
-// The Parent field is optional. It is used for event that will be recorded in the entity's parent
-// trace also.
+// TraceEventDesc is what the caller of AddTraceEvent should provide to describe
+// the event to be added to the channel trace.
+//
+// The Parent field is optional. It is used for an event that will be recorded
+// in the entity's parent trace.
 type TraceEventDesc struct {
 	Desc     string
 	Severity Severity
 	Parent   *TraceEventDesc
 }
 
-// AddTraceEvent adds trace related to the entity with specified id, using the provided TraceEventDesc.
-func AddTraceEvent(l grpclog.DepthLoggerV2, id int64, depth int, desc *TraceEventDesc) {
-	for d := desc; d != nil; d = d.Parent {
-		switch d.Severity {
-		case CtUnknown, CtInfo:
-			l.InfoDepth(depth+1, d.Desc)
-		case CtWarning:
-			l.WarningDepth(depth+1, d.Desc)
-		case CtError:
-			l.ErrorDepth(depth+1, d.Desc)
-		}
+// AddTraceEvent adds trace related to the entity with specified id, using the
+// provided TraceEventDesc.
+//
+// If channelz is not turned ON, this will simply log the event descriptions.
+func AddTraceEvent(l grpclog.DepthLoggerV2, id *Identifier, depth int, desc *TraceEventDesc) {
+	// Log only the trace description associated with the bottom most entity.
+	switch desc.Severity {
+	case CtUnknown, CtInfo:
+		l.InfoDepth(depth+1, withParens(id)+desc.Desc)
+	case CtWarning:
+		l.WarningDepth(depth+1, withParens(id)+desc.Desc)
+	case CtError:
+		l.ErrorDepth(depth+1, withParens(id)+desc.Desc)
 	}
+
 	if getMaxTraceEntry() == 0 {
 		return
 	}
-	db.get().traceEvent(id, desc)
+	if IsOn() {
+		db.get().traceEvent(id.Int(), desc)
+	}
 }
 
 // channelMap is the storage data structure for channelz.

vendor/google.golang.org/grpc/internal/channelz/id.go

@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import "fmt"
+
+// Identifier is an opaque identifier which uniquely identifies an entity in the
+// channelz database.
+type Identifier struct {
+	typ RefChannelType
+	id  int64
+	str string
+	pid *Identifier
+}
+
+// Type returns the entity type corresponding to id.
+func (id *Identifier) Type() RefChannelType {
+	return id.typ
+}
+
+// Int returns the integer identifier corresponding to id.
+func (id *Identifier) Int() int64 {
+	return id.id
+}
+
+// String returns a string representation of the entity corresponding to id.
+//
+// This includes some information about the parent as well. Examples:
+// Top-level channel: [Channel #channel-number]
+// Nested channel:    [Channel #parent-channel-number Channel #channel-number]
+// Sub channel:       [Channel #parent-channel SubChannel #subchannel-number]
+func (id *Identifier) String() string {
+	return id.str
+}
+
+// Equal returns true if other is the same as id.
+func (id *Identifier) Equal(other *Identifier) bool {
+	if (id != nil) != (other != nil) {
+		return false
+	}
+	if id == nil && other == nil {
+		return true
+	}
+	return id.typ == other.typ && id.id == other.id && id.pid == other.pid
+}
+
+// NewIdentifierForTesting returns a new opaque identifier to be used only for
+// testing purposes.
+func NewIdentifierForTesting(typ RefChannelType, id int64, pid *Identifier) *Identifier {
+	return newIdentifer(typ, id, pid)
+}
+
+func newIdentifer(typ RefChannelType, id int64, pid *Identifier) *Identifier {
+	str := fmt.Sprintf("%s #%d", typ, id)
+	if pid != nil {
+		str = fmt.Sprintf("%s %s", pid, str)
+	}
+	return &Identifier{typ: typ, id: id, str: str, pid: pid}
+}

vendor/google.golang.org/grpc/internal/channelz/logging.go

@@ -26,77 +26,54 @@ import (
 
 var logger = grpclog.Component("channelz")
 
+func withParens(id *Identifier) string {
+	return "[" + id.String() + "] "
+}
+
 // Info logs and adds a trace event if channelz is on.
-func Info(l grpclog.DepthLoggerV2, id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtInfo,
-		})
-	} else {
-		l.InfoDepth(1, args...)
-	}
+func Info(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtInfo,
+	})
 }
 
 // Infof logs and adds a trace event if channelz is on.
-func Infof(l grpclog.DepthLoggerV2, id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtInfo,
-		})
-	} else {
-		l.InfoDepth(1, msg)
-	}
+func Infof(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtInfo,
+	})
 }
 
 // Warning logs and adds a trace event if channelz is on.
-func Warning(l grpclog.DepthLoggerV2, id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtWarning,
-		})
-	} else {
-		l.WarningDepth(1, args...)
-	}
+func Warning(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtWarning,
+	})
 }
 
 // Warningf logs and adds a trace event if channelz is on.
-func Warningf(l grpclog.DepthLoggerV2, id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtWarning,
-		})
-	} else {
-		l.WarningDepth(1, msg)
-	}
+func Warningf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtWarning,
+	})
 }
 
 // Error logs and adds a trace event if channelz is on.
-func Error(l grpclog.DepthLoggerV2, id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtError,
-		})
-	} else {
-		l.ErrorDepth(1, args...)
-	}
+func Error(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtError,
+	})
 }
 
 // Errorf logs and adds a trace event if channelz is on.
-func Errorf(l grpclog.DepthLoggerV2, id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtError,
-		})
-	} else {
-		l.ErrorDepth(1, msg)
-	}
+func Errorf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtError,
+	})
 }

vendor/google.golang.org/grpc/internal/channelz/types.go

@@ -686,12 +686,33 @@ const (
 type RefChannelType int
 
 const (
+	// RefUnknown indicates an unknown entity type, the zero value for this type.
+	RefUnknown RefChannelType = iota
 	// RefChannel indicates the referenced entity is a Channel.
-	RefChannel RefChannelType = iota
+	RefChannel
 	// RefSubChannel indicates the referenced entity is a SubChannel.
 	RefSubChannel
+	// RefServer indicates the referenced entity is a Server.
+	RefServer
+	// RefListenSocket indicates the referenced entity is a ListenSocket.
+	RefListenSocket
+	// RefNormalSocket indicates the referenced entity is a NormalSocket.
+	RefNormalSocket
 )
 
+var refChannelTypeToString = map[RefChannelType]string{
+	RefUnknown:      "Unknown",
+	RefChannel:      "Channel",
+	RefSubChannel:   "SubChannel",
+	RefServer:       "Server",
+	RefListenSocket: "ListenSocket",
+	RefNormalSocket: "NormalSocket",
+}
+
+func (r RefChannelType) String() string {
+	return refChannelTypeToString[r]
+}
+
 func (c *channelTrace) dumpData() *ChannelTrace {
 	c.mu.Lock()
 	ct := &ChannelTrace{EventNum: c.eventCount, CreationTime: c.createdTime}

vendor/google.golang.org/grpc/internal/internal.go

@@ -85,3 +85,9 @@ const (
 	// that supports backend returned by grpclb balancer.
 	CredsBundleModeBackendFromBalancer = "backend-from-balancer"
 )
+
+// RLSLoadBalancingPolicyName is the name of the RLS LB policy.
+//
+// It currently has an experimental suffix which would be removed once
+// end-to-end testing of the policy is completed.
+const RLSLoadBalancingPolicyName = "rls_experimental"

vendor/google.golang.org/grpc/internal/metadata/metadata.go

@@ -22,6 +22,9 @@
 package metadata
 
 import (
+	"fmt"
+	"strings"
+
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/resolver"
 )
@@ -72,3 +75,46 @@ func Set(addr resolver.Address, md metadata.MD) resolver.Address {
 	addr.Attributes = addr.Attributes.WithValue(mdKey, mdValue(md))
 	return addr
 }
+
+// Validate returns an error if the input md contains invalid keys or values.
+//
+// If the header is not a pseudo-header, the following items are checked:
+// - header names must contain one or more characters from this set [0-9 a-z _ - .].
+// - if the header-name ends with a "-bin" suffix, no validation of the header value is performed.
+// - otherwise, the header value must contain one or more characters from the set [%x20-%x7E].
+func Validate(md metadata.MD) error {
+	for k, vals := range md {
+		// pseudo-header will be ignored
+		if k[0] == ':' {
+			continue
+		}
+		// check key, for i that saving a conversion if not using for range
+		for i := 0; i < len(k); i++ {
+			r := k[i]
+			if !(r >= 'a' && r <= 'z') && !(r >= '0' && r <= '9') && r != '.' && r != '-' && r != '_' {
+				return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", k)
+			}
+		}
+		if strings.HasSuffix(k, "-bin") {
+			continue
+		}
+		// check value
+		for _, val := range vals {
+			if hasNotPrintable(val) {
+				return fmt.Errorf("header key %q contains value with non-printable ASCII characters", k)
+			}
+		}
+	}
+	return nil
+}
+
+// hasNotPrintable return true if msg contains any characters which are not in %x20-%x7E
+func hasNotPrintable(msg string) bool {
+	// for i that saving a conversion if not using for range
+	for i := 0; i < len(msg); i++ {
+		if msg[i] < 0x20 || msg[i] > 0x7E {
+			return true
+		}
+	}
+	return false
+}

vendor/google.golang.org/grpc/internal/pretty/pretty.go

@@ -0,0 +1,82 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package pretty defines helper functions to pretty-print structs for logging.
+package pretty
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
+	"github.com/golang/protobuf/jsonpb"
+	protov1 "github.com/golang/protobuf/proto"
+	"google.golang.org/protobuf/encoding/protojson"
+	protov2 "google.golang.org/protobuf/proto"
+)
+
+const jsonIndent = "  "
+
+// ToJSON marshals the input into a json string.
+//
+// If marshal fails, it falls back to fmt.Sprintf("%+v").
+func ToJSON(e interface{}) string {
+	switch ee := e.(type) {
+	case protov1.Message:
+		mm := jsonpb.Marshaler{Indent: jsonIndent}
+		ret, err := mm.MarshalToString(ee)
+		if err != nil {
+			// This may fail for proto.Anys, e.g. for xDS v2, LDS, the v2
+			// messages are not imported, and this will fail because the message
+			// is not found.
+			return fmt.Sprintf("%+v", ee)
+		}
+		return ret
+	case protov2.Message:
+		mm := protojson.MarshalOptions{
+			Multiline: true,
+			Indent:    jsonIndent,
+		}
+		ret, err := mm.Marshal(ee)
+		if err != nil {
+			// This may fail for proto.Anys, e.g. for xDS v2, LDS, the v2
+			// messages are not imported, and this will fail because the message
+			// is not found.
+			return fmt.Sprintf("%+v", ee)
+		}
+		return string(ret)
+	default:
+		ret, err := json.MarshalIndent(ee, "", jsonIndent)
+		if err != nil {
+			return fmt.Sprintf("%+v", ee)
+		}
+		return string(ret)
+	}
+}
+
+// FormatJSON formats the input json bytes with indentation.
+//
+// If Indent fails, it returns the unchanged input as string.
+func FormatJSON(b []byte) string {
+	var out bytes.Buffer
+	err := json.Indent(&out, b, "", jsonIndent)
+	if err != nil {
+		return string(b)
+	}
+	return out.String()
+}

vendor/google.golang.org/grpc/internal/transport/controlbuf.go

@@ -137,6 +137,7 @@ type earlyAbortStream struct {
 	streamID       uint32
 	contentSubtype string
 	status         *status.Status
+	rst            bool
 }
 
 func (*earlyAbortStream) isTransportResponseFrame() bool { return false }
@@ -786,6 +787,11 @@ func (l *loopyWriter) earlyAbortStreamHandler(eas *earlyAbortStream) error {
 	if err := l.writeHeader(eas.streamID, true, headerFields, nil); err != nil {
 		return err
 	}
+	if eas.rst {
+		if err := l.framer.fr.WriteRSTStream(eas.streamID, http2.ErrCodeNo); err != nil {
+			return err
+		}
+	}
 	return nil
 }
 

vendor/google.golang.org/grpc/internal/transport/http2_client.go

@@ -132,7 +132,7 @@ type http2Client struct {
 	kpDormant bool
 
 	// Fields below are for channelz metric collection.
-	channelzID int64 // channelz unique identification number
+	channelzID *channelz.Identifier
 	czData     *channelzData
 
 	onGoAway func(GoAwayReason)
@@ -351,8 +351,9 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		}
 		t.statsHandler.HandleConn(t.ctx, connBegin)
 	}
-	if channelz.IsOn() {
-		t.channelzID = channelz.RegisterNormalSocket(t, opts.ChannelzParentID, fmt.Sprintf("%s -> %s", t.localAddr, t.remoteAddr))
+	t.channelzID, err = channelz.RegisterNormalSocket(t, opts.ChannelzParentID, fmt.Sprintf("%s -> %s", t.localAddr, t.remoteAddr))
+	if err != nil {
+		return nil, err
 	}
 	if t.keepaliveEnabled {
 		t.kpDormancyCond = sync.NewCond(&t.mu)
@@ -630,8 +631,8 @@ func (t *http2Client) getCallAuthData(ctx context.Context, audience string, call
 // the wire.  However, there are two notable exceptions:
 //
 // 1. If the stream headers violate the max header list size allowed by the
-//    server.  In this case there is no reason to retry at all, as it is
-//    assumed the RPC would continue to fail on subsequent attempts.
+//    server.  It's possible this could succeed on another transport, even if
+//    it's unlikely, but do not transparently retry.
 // 2. If the credentials errored when requesting their headers.  In this case,
 //    it's possible a retry can fix the problem, but indefinitely transparently
 //    retrying is not appropriate as it is likely the credentials, if they can
@@ -639,8 +640,7 @@ func (t *http2Client) getCallAuthData(ctx context.Context, audience string, call
 type NewStreamError struct {
 	Err error
 
-	DoNotRetry            bool
-	DoNotTransparentRetry bool
+	AllowTransparentRetry bool
 }
 
 func (e NewStreamError) Error() string {
@@ -649,11 +649,11 @@ func (e NewStreamError) Error() string {
 
 // NewStream creates a stream and registers it into the transport as "active"
 // streams.  All non-nil errors returned will be *NewStreamError.
-func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Stream, err error) {
+func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error) {
 	ctx = peer.NewContext(ctx, t.getPeer())
 	headerFields, err := t.createHeaderFields(ctx, callHdr)
 	if err != nil {
-		return nil, &NewStreamError{Err: err, DoNotTransparentRetry: true}
+		return nil, &NewStreamError{Err: err, AllowTransparentRetry: false}
 	}
 	s := t.newStream(ctx, callHdr)
 	cleanup := func(err error) {
@@ -753,13 +753,14 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 			return true
 		}, hdr)
 		if err != nil {
-			return nil, &NewStreamError{Err: err}
+			// Connection closed.
+			return nil, &NewStreamError{Err: err, AllowTransparentRetry: true}
 		}
 		if success {
 			break
 		}
 		if hdrListSizeErr != nil {
-			return nil, &NewStreamError{Err: hdrListSizeErr, DoNotRetry: true}
+			return nil, &NewStreamError{Err: hdrListSizeErr}
 		}
 		firstTry = false
 		select {
@@ -767,9 +768,9 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 		case <-ctx.Done():
 			return nil, &NewStreamError{Err: ContextErr(ctx.Err())}
 		case <-t.goAway:
-			return nil, &NewStreamError{Err: errStreamDrain}
+			return nil, &NewStreamError{Err: errStreamDrain, AllowTransparentRetry: true}
 		case <-t.ctx.Done():
-			return nil, &NewStreamError{Err: ErrConnClosing}
+			return nil, &NewStreamError{Err: ErrConnClosing, AllowTransparentRetry: true}
 		}
 	}
 	if t.statsHandler != nil {
@@ -898,9 +899,7 @@ func (t *http2Client) Close(err error) {
 	t.controlBuf.finish()
 	t.cancel()
 	t.conn.Close()
-	if channelz.IsOn() {
-		channelz.RemoveEntry(t.channelzID)
-	}
+	channelz.RemoveEntry(t.channelzID)
 	// Append info about previous goaways if there were any, since this may be important
 	// for understanding the root cause for this connection to be closed.
 	_, goAwayDebugMessage := t.GetGoAwayReason()

vendor/google.golang.org/grpc/internal/transport/http2_server.go

@@ -21,7 +21,6 @@ package transport
 import (
 	"bytes"
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"math"
@@ -36,6 +35,7 @@ import (
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
 	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/internal/syscall"
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
@@ -52,10 +52,10 @@ import (
 var (
 	// ErrIllegalHeaderWrite indicates that setting header is illegal because of
 	// the stream's state.
-	ErrIllegalHeaderWrite = errors.New("transport: the stream is done or WriteHeader was already called")
+	ErrIllegalHeaderWrite = status.Error(codes.Internal, "transport: SendHeader called multiple times")
 	// ErrHeaderListSizeLimitViolation indicates that the header list size is larger
 	// than the limit set by peer.
-	ErrHeaderListSizeLimitViolation = errors.New("transport: trying to send header list size larger than the limit set by peer")
+	ErrHeaderListSizeLimitViolation = status.Error(codes.Internal, "transport: trying to send header list size larger than the limit set by peer")
 )
 
 // serverConnectionCounter counts the number of connections a server has seen
@@ -117,7 +117,7 @@ type http2Server struct {
 	idle time.Time
 
 	// Fields below are for channelz metric collection.
-	channelzID int64 // channelz unique identification number
+	channelzID *channelz.Identifier
 	czData     *channelzData
 	bufferPool *bufferPool
 
@@ -231,6 +231,11 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	if kp.Timeout == 0 {
 		kp.Timeout = defaultServerKeepaliveTimeout
 	}
+	if kp.Time != infinity {
+		if err = syscall.SetTCPUserTimeout(conn, kp.Timeout); err != nil {
+			return nil, connectionErrorf(false, err, "transport: failed to set TCP_USER_TIMEOUT: %v", err)
+		}
+	}
 	kep := config.KeepalivePolicy
 	if kep.MinTime == 0 {
 		kep.MinTime = defaultKeepalivePolicyMinTime
@@ -275,12 +280,12 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 		connBegin := &stats.ConnBegin{}
 		t.stats.HandleConn(t.ctx, connBegin)
 	}
-	if channelz.IsOn() {
-		t.channelzID = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.remoteAddr, t.localAddr))
+	t.channelzID, err = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.remoteAddr, t.localAddr))
+	if err != nil {
+		return nil, err
 	}
 
 	t.connectionID = atomic.AddUint64(&serverConnectionCounter, 1)
-
 	t.framer.writer.Flush()
 
 	defer func() {
@@ -443,6 +448,7 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 			streamID:       streamID,
 			contentSubtype: s.contentSubtype,
 			status:         status.New(codes.Internal, errMsg),
+			rst:            !frame.StreamEnded(),
 		})
 		return false
 	}
@@ -516,14 +522,16 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	}
 	if httpMethod != http.MethodPost {
 		t.mu.Unlock()
+		errMsg := fmt.Sprintf("http2Server.operateHeaders parsed a :method field: %v which should be POST", httpMethod)
 		if logger.V(logLevel) {
-			logger.Infof("transport: http2Server.operateHeaders parsed a :method field: %v which should be POST", httpMethod)
+			logger.Infof("transport: %v", errMsg)
 		}
-		t.controlBuf.put(&cleanupStream{
-			streamID: streamID,
-			rst:      true,
-			rstCode:  http2.ErrCodeProtocol,
-			onWrite:  func() {},
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     405,
+			streamID:       streamID,
+			contentSubtype: s.contentSubtype,
+			status:         status.New(codes.Internal, errMsg),
+			rst:            !frame.StreamEnded(),
 		})
 		s.cancel()
 		return false
@@ -544,6 +552,7 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 				streamID:       s.id,
 				contentSubtype: s.contentSubtype,
 				status:         stat,
+				rst:            !frame.StreamEnded(),
 			})
 			return false
 		}
@@ -925,11 +934,25 @@ func (t *http2Server) checkForHeaderListSize(it interface{}) bool {
 	return true
 }
 
+func (t *http2Server) streamContextErr(s *Stream) error {
+	select {
+	case <-t.done:
+		return ErrConnClosing
+	default:
+	}
+	return ContextErr(s.ctx.Err())
+}
+
 // WriteHeader sends the header metadata md back to the client.
 func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
-	if s.updateHeaderSent() || s.getState() == streamDone {
+	if s.updateHeaderSent() {
 		return ErrIllegalHeaderWrite
 	}
+
+	if s.getState() == streamDone {
+		return t.streamContextErr(s)
+	}
+
 	s.hdrMu.Lock()
 	if md.Len() > 0 {
 		if s.header.Len() > 0 {
@@ -940,7 +963,7 @@ func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
 	}
 	if err := t.writeHeaderLocked(s); err != nil {
 		s.hdrMu.Unlock()
-		return err
+		return status.Convert(err).Err()
 	}
 	s.hdrMu.Unlock()
 	return nil
@@ -1056,23 +1079,12 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 func (t *http2Server) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
 	if !s.isHeaderSent() { // Headers haven't been written yet.
 		if err := t.WriteHeader(s, nil); err != nil {
-			if _, ok := err.(ConnectionError); ok {
-				return err
-			}
-			// TODO(mmukhi, dfawley): Make sure this is the right code to return.
-			return status.Errorf(codes.Internal, "transport: %v", err)
+			return err
 		}
 	} else {
 		// Writing headers checks for this condition.
 		if s.getState() == streamDone {
-			// TODO(mmukhi, dfawley): Should the server write also return io.EOF?
-			s.cancel()
-			select {
-			case <-t.done:
-				return ErrConnClosing
-			default:
-			}
-			return ContextErr(s.ctx.Err())
+			return t.streamContextErr(s)
 		}
 	}
 	df := &dataFrame{
@@ -1082,12 +1094,7 @@ func (t *http2Server) Write(s *Stream, hdr []byte, data []byte, opts *Options) e
 		onEachWrite: t.setResetPingStrikes,
 	}
 	if err := s.wq.get(int32(len(hdr) + len(data))); err != nil {
-		select {
-		case <-t.done:
-			return ErrConnClosing
-		default:
-		}
-		return ContextErr(s.ctx.Err())
+		return t.streamContextErr(s)
 	}
 	return t.controlBuf.put(df)
 }
@@ -1210,9 +1217,7 @@ func (t *http2Server) Close() {
 	if err := t.conn.Close(); err != nil && logger.V(logLevel) {
 		logger.Infof("transport: error closing conn during Close: %v", err)
 	}
-	if channelz.IsOn() {
-		channelz.RemoveEntry(t.channelzID)
-	}
+	channelz.RemoveEntry(t.channelzID)
 	// Cancel all active streams.
 	for _, s := range streams {
 		s.cancel()
@@ -1225,10 +1230,6 @@ func (t *http2Server) Close() {
 
 // deleteStream deletes the stream s from transport's active streams.
 func (t *http2Server) deleteStream(s *Stream, eosReceived bool) {
-	// In case stream sending and receiving are invoked in separate
-	// goroutines (e.g., bi-directional streaming), cancel needs to be
-	// called to interrupt the potential blocking on other goroutines.
-	s.cancel()
 
 	t.mu.Lock()
 	if _, ok := t.activeStreams[s.id]; ok {
@@ -1250,6 +1251,11 @@ func (t *http2Server) deleteStream(s *Stream, eosReceived bool) {
 
 // finishStream closes the stream and puts the trailing headerFrame into controlbuf.
 func (t *http2Server) finishStream(s *Stream, rst bool, rstCode http2.ErrCode, hdr *headerFrame, eosReceived bool) {
+	// In case stream sending and receiving are invoked in separate
+	// goroutines (e.g., bi-directional streaming), cancel needs to be
+	// called to interrupt the potential blocking on other goroutines.
+	s.cancel()
+
 	oldState := s.swapState(streamDone)
 	if oldState == streamDone {
 		// If the stream was already done, return.
@@ -1269,6 +1275,11 @@ func (t *http2Server) finishStream(s *Stream, rst bool, rstCode http2.ErrCode, h
 
 // closeStream clears the footprint of a stream when the stream is not needed any more.
 func (t *http2Server) closeStream(s *Stream, rst bool, rstCode http2.ErrCode, eosReceived bool) {
+	// In case stream sending and receiving are invoked in separate
+	// goroutines (e.g., bi-directional streaming), cancel needs to be
+	// called to interrupt the potential blocking on other goroutines.
+	s.cancel()
+
 	s.swapState(streamDone)
 	t.deleteStream(s, eosReceived)
 

vendor/google.golang.org/grpc/internal/transport/transport.go

@@ -34,6 +34,7 @@ import (
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/resolver"
@@ -529,7 +530,7 @@ type ServerConfig struct {
 	InitialConnWindowSize int32
 	WriteBufferSize       int
 	ReadBufferSize        int
-	ChannelzParentID      int64
+	ChannelzParentID      *channelz.Identifier
 	MaxHeaderListSize     *uint32
 	HeaderTableSize       *uint32
 }
@@ -563,7 +564,7 @@ type ConnectOptions struct {
 	// ReadBufferSize sets the size of read buffer, which in turn determines how much data can be read at most for one read syscall.
 	ReadBufferSize int
 	// ChannelzParentID sets the addrConn id which initiate the creation of this client transport.
-	ChannelzParentID int64
+	ChannelzParentID *channelz.Identifier
 	// MaxHeaderListSize sets the max (uncompressed) size of header list that is prepared to be received.
 	MaxHeaderListSize *uint32
 	// UseProxy specifies if a proxy should be used.

vendor/google.golang.org/grpc/metadata/metadata.go

@@ -188,7 +188,9 @@ func FromIncomingContext(ctx context.Context) (MD, bool) {
 		// map, and there's no guarantee that the MD attached to the context is
 		// created using our helper functions.
 		key := strings.ToLower(k)
-		out[key] = v
+		s := make([]string, len(v))
+		copy(s, v)
+		out[key] = s
 	}
 	return out, true
 }
@@ -226,7 +228,9 @@ func FromOutgoingContext(ctx context.Context) (MD, bool) {
 		// map, and there's no guarantee that the MD attached to the context is
 		// created using our helper functions.
 		key := strings.ToLower(k)
-		out[key] = v
+		s := make([]string, len(v))
+		copy(s, v)
+		out[key] = s
 	}
 	for _, added := range raw.added {
 		if len(added)%2 == 1 {

vendor/google.golang.org/grpc/picker_wrapper.go

@@ -131,7 +131,7 @@ func (pw *pickerWrapper) pick(ctx context.Context, failfast bool, info balancer.
 			}
 			if _, ok := status.FromError(err); ok {
 				// Status error: end the RPC unconditionally with this status.
-				return nil, nil, err
+				return nil, nil, dropError{error: err}
 			}
 			// For all other errors, wait for ready RPCs should block and other
 			// RPCs should fail with unavailable.
@@ -175,3 +175,9 @@ func (pw *pickerWrapper) close() {
 	pw.done = true
 	close(pw.blockingCh)
 }
+
+// dropError is a wrapper error that indicates the LB policy wishes to drop the
+// RPC and not retry it.
+type dropError struct {
+	error
+}

vendor/google.golang.org/grpc/pickfirst.go

@@ -44,79 +44,107 @@ func (*pickfirstBuilder) Name() string {
 }
 
 type pickfirstBalancer struct {
-	state connectivity.State
-	cc    balancer.ClientConn
-	sc    balancer.SubConn
+	state   connectivity.State
+	cc      balancer.ClientConn
+	subConn balancer.SubConn
 }
 
 func (b *pickfirstBalancer) ResolverError(err error) {
-	switch b.state {
-	case connectivity.TransientFailure, connectivity.Idle, connectivity.Connecting:
-		// Set a failing picker if we don't have a good picker.
-		b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.TransientFailure,
-			Picker: &picker{err: fmt.Errorf("name resolver error: %v", err)},
-		})
-	}
 	if logger.V(2) {
 		logger.Infof("pickfirstBalancer: ResolverError called with error %v", err)
 	}
+	if b.subConn == nil {
+		b.state = connectivity.TransientFailure
+	}
+
+	if b.state != connectivity.TransientFailure {
+		// The picker will not change since the balancer does not currently
+		// report an error.
+		return
+	}
+	b.cc.UpdateState(balancer.State{
+		ConnectivityState: connectivity.TransientFailure,
+		Picker:            &picker{err: fmt.Errorf("name resolver error: %v", err)},
+	})
 }
 
-func (b *pickfirstBalancer) UpdateClientConnState(cs balancer.ClientConnState) error {
-	if len(cs.ResolverState.Addresses) == 0 {
+func (b *pickfirstBalancer) UpdateClientConnState(state balancer.ClientConnState) error {
+	if len(state.ResolverState.Addresses) == 0 {
+		// The resolver reported an empty address list. Treat it like an error by
+		// calling b.ResolverError.
+		if b.subConn != nil {
+			// Remove the old subConn. All addresses were removed, so it is no longer
+			// valid.
+			b.cc.RemoveSubConn(b.subConn)
+			b.subConn = nil
+		}
 		b.ResolverError(errors.New("produced zero addresses"))
 		return balancer.ErrBadResolverState
 	}
-	if b.sc == nil {
-		var err error
-		b.sc, err = b.cc.NewSubConn(cs.ResolverState.Addresses, balancer.NewSubConnOptions{})
-		if err != nil {
-			if logger.V(2) {
-				logger.Errorf("pickfirstBalancer: failed to NewSubConn: %v", err)
-			}
-			b.state = connectivity.TransientFailure
-			b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.TransientFailure,
-				Picker: &picker{err: fmt.Errorf("error creating connection: %v", err)},
-			})
-			return balancer.ErrBadResolverState
-		}
-		b.state = connectivity.Idle
-		b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.Idle, Picker: &picker{result: balancer.PickResult{SubConn: b.sc}}})
-		b.sc.Connect()
-	} else {
-		b.cc.UpdateAddresses(b.sc, cs.ResolverState.Addresses)
-		b.sc.Connect()
+
+	if b.subConn != nil {
+		b.cc.UpdateAddresses(b.subConn, state.ResolverState.Addresses)
+		return nil
 	}
+
+	subConn, err := b.cc.NewSubConn(state.ResolverState.Addresses, balancer.NewSubConnOptions{})
+	if err != nil {
+		if logger.V(2) {
+			logger.Errorf("pickfirstBalancer: failed to NewSubConn: %v", err)
+		}
+		b.state = connectivity.TransientFailure
+		b.cc.UpdateState(balancer.State{
+			ConnectivityState: connectivity.TransientFailure,
+			Picker:            &picker{err: fmt.Errorf("error creating connection: %v", err)},
+		})
+		return balancer.ErrBadResolverState
+	}
+	b.subConn = subConn
+	b.state = connectivity.Idle
+	b.cc.UpdateState(balancer.State{
+		ConnectivityState: connectivity.Idle,
+		Picker:            &picker{result: balancer.PickResult{SubConn: b.subConn}},
+	})
+	b.subConn.Connect()
 	return nil
 }
 
-func (b *pickfirstBalancer) UpdateSubConnState(sc balancer.SubConn, s balancer.SubConnState) {
+func (b *pickfirstBalancer) UpdateSubConnState(subConn balancer.SubConn, state balancer.SubConnState) {
 	if logger.V(2) {
-		logger.Infof("pickfirstBalancer: UpdateSubConnState: %p, %v", sc, s)
+		logger.Infof("pickfirstBalancer: UpdateSubConnState: %p, %v", subConn, state)
 	}
-	if b.sc != sc {
+	if b.subConn != subConn {
 		if logger.V(2) {
-			logger.Infof("pickfirstBalancer: ignored state change because sc is not recognized")
+			logger.Infof("pickfirstBalancer: ignored state change because subConn is not recognized")
 		}
 		return
 	}
-	b.state = s.ConnectivityState
-	if s.ConnectivityState == connectivity.Shutdown {
-		b.sc = nil
+	b.state = state.ConnectivityState
+	if state.ConnectivityState == connectivity.Shutdown {
+		b.subConn = nil
 		return
 	}
 
-	switch s.ConnectivityState {
+	switch state.ConnectivityState {
 	case connectivity.Ready:
-		b.cc.UpdateState(balancer.State{ConnectivityState: s.ConnectivityState, Picker: &picker{result: balancer.PickResult{SubConn: sc}}})
+		b.cc.UpdateState(balancer.State{
+			ConnectivityState: state.ConnectivityState,
+			Picker:            &picker{result: balancer.PickResult{SubConn: subConn}},
+		})
 	case connectivity.Connecting:
-		b.cc.UpdateState(balancer.State{ConnectivityState: s.ConnectivityState, Picker: &picker{err: balancer.ErrNoSubConnAvailable}})
+		b.cc.UpdateState(balancer.State{
+			ConnectivityState: state.ConnectivityState,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
 	case connectivity.Idle:
-		b.cc.UpdateState(balancer.State{ConnectivityState: s.ConnectivityState, Picker: &idlePicker{sc: sc}})
+		b.cc.UpdateState(balancer.State{
+			ConnectivityState: state.ConnectivityState,
+			Picker:            &idlePicker{subConn: subConn},
+		})
 	case connectivity.TransientFailure:
 		b.cc.UpdateState(balancer.State{
-			ConnectivityState: s.ConnectivityState,
-			Picker:            &picker{err: s.ConnectionError},
+			ConnectivityState: state.ConnectivityState,
+			Picker:            &picker{err: state.ConnectionError},
 		})
 	}
 }
@@ -125,8 +153,8 @@ func (b *pickfirstBalancer) Close() {
 }
 
 func (b *pickfirstBalancer) ExitIdle() {
-	if b.sc != nil && b.state == connectivity.Idle {
-		b.sc.Connect()
+	if b.subConn != nil && b.state == connectivity.Idle {
+		b.subConn.Connect()
 	}
 }
 
@@ -135,18 +163,18 @@ type picker struct {
 	err    error
 }
 
-func (p *picker) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
+func (p *picker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
 	return p.result, p.err
 }
 
 // idlePicker is used when the SubConn is IDLE and kicks the SubConn into
 // CONNECTING when Pick is called.
 type idlePicker struct {
-	sc balancer.SubConn
+	subConn balancer.SubConn
 }
 
-func (i *idlePicker) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
-	i.sc.Connect()
+func (i *idlePicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+	i.subConn.Connect()
 	return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
 }
 

vendor/google.golang.org/grpc/resolver/resolver.go

@@ -27,6 +27,7 @@ import (
 
 	"google.golang.org/grpc/attributes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/pretty"
 	"google.golang.org/grpc/serviceconfig"
 )
 
@@ -139,13 +140,18 @@ type Address struct {
 
 // Equal returns whether a and o are identical.  Metadata is compared directly,
 // not with any recursive introspection.
-func (a *Address) Equal(o Address) bool {
+func (a Address) Equal(o Address) bool {
 	return a.Addr == o.Addr && a.ServerName == o.ServerName &&
 		a.Attributes.Equal(o.Attributes) &&
 		a.BalancerAttributes.Equal(o.BalancerAttributes) &&
 		a.Type == o.Type && a.Metadata == o.Metadata
 }
 
+// String returns JSON formatted string representation of the address.
+func (a Address) String() string {
+	return pretty.ToJSON(a)
+}
+
 // BuildOptions includes additional information for the builder to create
 // the resolver.
 type BuildOptions struct {

vendor/google.golang.org/grpc/resolver_conn_wrapper.go

@@ -19,7 +19,6 @@
 package grpc
 
 import (
-	"fmt"
 	"strings"
 	"sync"
 
@@ -27,6 +26,7 @@ import (
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcsync"
+	"google.golang.org/grpc/internal/pretty"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/serviceconfig"
 )
@@ -97,10 +97,7 @@ func (ccr *ccResolverWrapper) UpdateState(s resolver.State) error {
 	if ccr.done.HasFired() {
 		return nil
 	}
-	channelz.Infof(logger, ccr.cc.channelzID, "ccResolverWrapper: sending update to cc: %v", s)
-	if channelz.IsOn() {
-		ccr.addChannelzTraceEvent(s)
-	}
+	ccr.addChannelzTraceEvent(s)
 	ccr.curState = s
 	if err := ccr.cc.updateResolverState(ccr.curState, nil); err == balancer.ErrBadResolverState {
 		return balancer.ErrBadResolverState
@@ -125,10 +122,7 @@ func (ccr *ccResolverWrapper) NewAddress(addrs []resolver.Address) {
 	if ccr.done.HasFired() {
 		return
 	}
-	channelz.Infof(logger, ccr.cc.channelzID, "ccResolverWrapper: sending new addresses to cc: %v", addrs)
-	if channelz.IsOn() {
-		ccr.addChannelzTraceEvent(resolver.State{Addresses: addrs, ServiceConfig: ccr.curState.ServiceConfig})
-	}
+	ccr.addChannelzTraceEvent(resolver.State{Addresses: addrs, ServiceConfig: ccr.curState.ServiceConfig})
 	ccr.curState.Addresses = addrs
 	ccr.cc.updateResolverState(ccr.curState, nil)
 }
@@ -141,7 +135,7 @@ func (ccr *ccResolverWrapper) NewServiceConfig(sc string) {
 	if ccr.done.HasFired() {
 		return
 	}
-	channelz.Infof(logger, ccr.cc.channelzID, "ccResolverWrapper: got new service config: %v", sc)
+	channelz.Infof(logger, ccr.cc.channelzID, "ccResolverWrapper: got new service config: %s", sc)
 	if ccr.cc.dopts.disableServiceConfig {
 		channelz.Info(logger, ccr.cc.channelzID, "Service config lookups disabled; ignoring config")
 		return
@@ -151,9 +145,7 @@ func (ccr *ccResolverWrapper) NewServiceConfig(sc string) {
 		channelz.Warningf(logger, ccr.cc.channelzID, "ccResolverWrapper: error parsing service config: %v", scpr.Err)
 		return
 	}
-	if channelz.IsOn() {
-		ccr.addChannelzTraceEvent(resolver.State{Addresses: ccr.curState.Addresses, ServiceConfig: scpr})
-	}
+	ccr.addChannelzTraceEvent(resolver.State{Addresses: ccr.curState.Addresses, ServiceConfig: scpr})
 	ccr.curState.ServiceConfig = scpr
 	ccr.cc.updateResolverState(ccr.curState, nil)
 }
@@ -180,8 +172,5 @@ func (ccr *ccResolverWrapper) addChannelzTraceEvent(s resolver.State) {
 	} else if len(ccr.curState.Addresses) == 0 && len(s.Addresses) > 0 {
 		updates = append(updates, "resolver returned new addresses")
 	}
-	channelz.AddTraceEvent(logger, ccr.cc.channelzID, 0, &channelz.TraceEventDesc{
-		Desc:     fmt.Sprintf("Resolver state updated: %+v (%v)", s, strings.Join(updates, "; ")),
-		Severity: channelz.CtInfo,
-	})
+	channelz.Infof(logger, ccr.cc.channelzID, "Resolver state updated: %s (%v)", pretty.ToJSON(s), strings.Join(updates, "; "))
 }

vendor/google.golang.org/grpc/server.go

@@ -134,7 +134,7 @@ type Server struct {
 	channelzRemoveOnce sync.Once
 	serveWG            sync.WaitGroup // counts active Serve goroutines for GracefulStop
 
-	channelzID int64 // channelz unique identification number
+	channelzID *channelz.Identifier
 	czData     *channelzData
 
 	serverWorkerChannels []chan *serverWorkerData
@@ -584,9 +584,8 @@ func NewServer(opt ...ServerOption) *Server {
 		s.initServerWorkers()
 	}
 
-	if channelz.IsOn() {
-		s.channelzID = channelz.RegisterServer(&channelzServer{s}, "")
-	}
+	s.channelzID = channelz.RegisterServer(&channelzServer{s}, "")
+	channelz.Info(logger, s.channelzID, "Server created")
 	return s
 }
 
@@ -712,7 +711,7 @@ var ErrServerStopped = errors.New("grpc: the server has been stopped")
 
 type listenSocket struct {
 	net.Listener
-	channelzID int64
+	channelzID *channelz.Identifier
 }
 
 func (l *listenSocket) ChannelzMetric() *channelz.SocketInternalMetric {
@@ -724,9 +723,8 @@ func (l *listenSocket) ChannelzMetric() *channelz.SocketInternalMetric {
 
 func (l *listenSocket) Close() error {
 	err := l.Listener.Close()
-	if channelz.IsOn() {
-		channelz.RemoveEntry(l.channelzID)
-	}
+	channelz.RemoveEntry(l.channelzID)
+	channelz.Info(logger, l.channelzID, "ListenSocket deleted")
 	return err
 }
 
@@ -759,11 +757,6 @@ func (s *Server) Serve(lis net.Listener) error {
 	ls := &listenSocket{Listener: lis}
 	s.lis[ls] = true
 
-	if channelz.IsOn() {
-		ls.channelzID = channelz.RegisterListenSocket(ls, s.channelzID, lis.Addr().String())
-	}
-	s.mu.Unlock()
-
 	defer func() {
 		s.mu.Lock()
 		if s.lis != nil && s.lis[ls] {
@@ -773,8 +766,16 @@ func (s *Server) Serve(lis net.Listener) error {
 		s.mu.Unlock()
 	}()
 
-	var tempDelay time.Duration // how long to sleep on accept failure
+	var err error
+	ls.channelzID, err = channelz.RegisterListenSocket(ls, s.channelzID, lis.Addr().String())
+	if err != nil {
+		s.mu.Unlock()
+		return err
+	}
+	s.mu.Unlock()
+	channelz.Info(logger, ls.channelzID, "ListenSocket created")
 
+	var tempDelay time.Duration // how long to sleep on accept failure
 	for {
 		rawConn, err := lis.Accept()
 		if err != nil {
@@ -1709,11 +1710,7 @@ func (s *Server) Stop() {
 		s.done.Fire()
 	}()
 
-	s.channelzRemoveOnce.Do(func() {
-		if channelz.IsOn() {
-			channelz.RemoveEntry(s.channelzID)
-		}
-	})
+	s.channelzRemoveOnce.Do(func() { channelz.RemoveEntry(s.channelzID) })
 
 	s.mu.Lock()
 	listeners := s.lis
@@ -1751,11 +1748,7 @@ func (s *Server) GracefulStop() {
 	s.quit.Fire()
 	defer s.done.Fire()
 
-	s.channelzRemoveOnce.Do(func() {
-		if channelz.IsOn() {
-			channelz.RemoveEntry(s.channelzID)
-		}
-	})
+	s.channelzRemoveOnce.Do(func() { channelz.RemoveEntry(s.channelzID) })
 	s.mu.Lock()
 	if s.conns == nil {
 		s.mu.Unlock()
@@ -1808,12 +1801,26 @@ func (s *Server) getCodec(contentSubtype string) baseCodec {
 	return codec
 }
 
-// SetHeader sets the header metadata.
-// When called multiple times, all the provided metadata will be merged.
-// All the metadata will be sent out when one of the following happens:
-//  - grpc.SendHeader() is called;
-//  - The first response is sent out;
-//  - An RPC status is sent out (error or success).
+// SetHeader sets the header metadata to be sent from the server to the client.
+// The context provided must be the context passed to the server's handler.
+//
+// Streaming RPCs should prefer the SetHeader method of the ServerStream.
+//
+// When called multiple times, all the provided metadata will be merged.  All
+// the metadata will be sent out when one of the following happens:
+//
+// - grpc.SendHeader is called, or for streaming handlers, stream.SendHeader.
+// - The first response message is sent.  For unary handlers, this occurs when
+//   the handler returns; for streaming handlers, this can happen when stream's
+//   SendMsg method is called.
+// - An RPC status is sent out (error or success).  This occurs when the handler
+//   returns.
+//
+// SetHeader will fail if called after any of the events above.
+//
+// The error returned is compatible with the status package.  However, the
+// status code will often not match the RPC status as seen by the client
+// application, and therefore, should not be relied upon for this purpose.
 func SetHeader(ctx context.Context, md metadata.MD) error {
 	if md.Len() == 0 {
 		return nil
@@ -1825,8 +1832,14 @@ func SetHeader(ctx context.Context, md metadata.MD) error {
 	return stream.SetHeader(md)
 }
 
-// SendHeader sends header metadata. It may be called at most once.
-// The provided md and headers set by SetHeader() will be sent.
+// SendHeader sends header metadata. It may be called at most once, and may not
+// be called after any event that causes headers to be sent (see SetHeader for
+// a complete list).  The provided md and headers set by SetHeader() will be
+// sent.
+//
+// The error returned is compatible with the status package.  However, the
+// status code will often not match the RPC status as seen by the client
+// application, and therefore, should not be relied upon for this purpose.
 func SendHeader(ctx context.Context, md metadata.MD) error {
 	stream := ServerTransportStreamFromContext(ctx)
 	if stream == nil {
@@ -1840,6 +1853,10 @@ func SendHeader(ctx context.Context, md metadata.MD) error {
 
 // SetTrailer sets the trailer metadata that will be sent when an RPC returns.
 // When called more than once, all the provided metadata will be merged.
+//
+// The error returned is compatible with the status package.  However, the
+// status code will often not match the RPC status as seen by the client
+// application, and therefore, should not be relied upon for this purpose.
 func SetTrailer(ctx context.Context, md metadata.MD) error {
 	if md.Len() == 0 {
 		return nil

vendor/google.golang.org/grpc/service_config.go

@@ -381,6 +381,9 @@ func init() {
 //
 // If any of them is NOT *ServiceConfig, return false.
 func equalServiceConfig(a, b serviceconfig.Config) bool {
+	if a == nil && b == nil {
+		return true
+	}
 	aa, ok := a.(*ServiceConfig)
 	if !ok {
 		return false

vendor/google.golang.org/grpc/stream.go

@@ -36,6 +36,7 @@ import (
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/internal/grpcutil"
+	imetadata "google.golang.org/grpc/internal/metadata"
 	iresolver "google.golang.org/grpc/internal/resolver"
 	"google.golang.org/grpc/internal/serviceconfig"
 	"google.golang.org/grpc/internal/transport"
@@ -166,6 +167,11 @@ func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, meth
 }
 
 func newClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (_ ClientStream, err error) {
+	if md, _, ok := metadata.FromOutgoingContextRaw(ctx); ok {
+		if err := imetadata.Validate(md); err != nil {
+			return nil, status.Error(codes.Internal, err.Error())
+		}
+	}
 	if channelz.IsOn() {
 		cc.incrCallsStarted()
 		defer func() {
@@ -297,14 +303,28 @@ func newClientStreamWithParams(ctx context.Context, desc *StreamDesc, cc *Client
 	}
 	cs.binlog = binarylog.GetMethodLogger(method)
 
-	if err := cs.newAttemptLocked(false /* isTransparent */); err != nil {
+	cs.attempt, err = cs.newAttemptLocked(false /* isTransparent */)
+	if err != nil {
 		cs.finish(err)
 		return nil, err
 	}
 
-	op := func(a *csAttempt) error { return a.newStream() }
+	// Pick the transport to use and create a new stream on the transport.
+	// Assign cs.attempt upon success.
+	op := func(a *csAttempt) error {
+		if err := a.getTransport(); err != nil {
+			return err
+		}
+		if err := a.newStream(); err != nil {
+			return err
+		}
+		// Because this operation is always called either here (while creating
+		// the clientStream) or by the retry code while locked when replaying
+		// the operation, it is safe to access cs.attempt directly.
+		cs.attempt = a
+		return nil
+	}
 	if err := cs.withRetry(op, func() { cs.bufferForRetryLocked(0, op) }); err != nil {
-		cs.finish(err)
 		return nil, err
 	}
 
@@ -343,9 +363,15 @@ func newClientStreamWithParams(ctx context.Context, desc *StreamDesc, cc *Client
 	return cs, nil
 }
 
-// newAttemptLocked creates a new attempt with a transport.
-// If it succeeds, then it replaces clientStream's attempt with this new attempt.
-func (cs *clientStream) newAttemptLocked(isTransparent bool) (retErr error) {
+// newAttemptLocked creates a new csAttempt without a transport or stream.
+func (cs *clientStream) newAttemptLocked(isTransparent bool) (*csAttempt, error) {
+	if err := cs.ctx.Err(); err != nil {
+		return nil, toRPCErr(err)
+	}
+	if err := cs.cc.ctx.Err(); err != nil {
+		return nil, ErrClientConnClosing
+	}
+
 	ctx := newContextWithRPCInfo(cs.ctx, cs.callInfo.failFast, cs.callInfo.codec, cs.cp, cs.comp)
 	method := cs.callHdr.Method
 	sh := cs.cc.dopts.copts.StatsHandler
@@ -379,27 +405,6 @@ func (cs *clientStream) newAttemptLocked(isTransparent bool) (retErr error) {
 		ctx = trace.NewContext(ctx, trInfo.tr)
 	}
 
-	newAttempt := &csAttempt{
-		ctx:          ctx,
-		beginTime:    beginTime,
-		cs:           cs,
-		dc:           cs.cc.dopts.dc,
-		statsHandler: sh,
-		trInfo:       trInfo,
-	}
-	defer func() {
-		if retErr != nil {
-			// This attempt is not set in the clientStream, so it's finish won't
-			// be called. Call it here for stats and trace in case they are not
-			// nil.
-			newAttempt.finish(retErr)
-		}
-	}()
-
-	if err := ctx.Err(); err != nil {
-		return toRPCErr(err)
-	}
-
 	if cs.cc.parsedTarget.Scheme == "xds" {
 		// Add extra metadata (metadata that will be added by transport) to context
 		// so the balancer can see them.
@@ -407,16 +412,32 @@ func (cs *clientStream) newAttemptLocked(isTransparent bool) (retErr error) {
 			"content-type", grpcutil.ContentType(cs.callHdr.ContentSubtype),
 		))
 	}
-	t, done, err := cs.cc.getTransport(ctx, cs.callInfo.failFast, cs.callHdr.Method)
+
+	return &csAttempt{
+		ctx:          ctx,
+		beginTime:    beginTime,
+		cs:           cs,
+		dc:           cs.cc.dopts.dc,
+		statsHandler: sh,
+		trInfo:       trInfo,
+	}, nil
+}
+
+func (a *csAttempt) getTransport() error {
+	cs := a.cs
+
+	var err error
+	a.t, a.done, err = cs.cc.getTransport(a.ctx, cs.callInfo.failFast, cs.callHdr.Method)
 	if err != nil {
+		if de, ok := err.(dropError); ok {
+			err = de.error
+			a.drop = true
+		}
 		return err
 	}
-	if trInfo != nil {
-		trInfo.firstLine.SetRemoteAddr(t.RemoteAddr())
+	if a.trInfo != nil {
+		a.trInfo.firstLine.SetRemoteAddr(a.t.RemoteAddr())
 	}
-	newAttempt.t = t
-	newAttempt.done = done
-	cs.attempt = newAttempt
 	return nil
 }
 
@@ -425,12 +446,21 @@ func (a *csAttempt) newStream() error {
 	cs.callHdr.PreviousAttempts = cs.numRetries
 	s, err := a.t.NewStream(a.ctx, cs.callHdr)
 	if err != nil {
-		// Return without converting to an RPC error so retry code can
-		// inspect.
-		return err
+		nse, ok := err.(*transport.NewStreamError)
+		if !ok {
+			// Unexpected.
+			return err
+		}
+
+		if nse.AllowTransparentRetry {
+			a.allowTransparentRetry = true
+		}
+
+		// Unwrap and convert error.
+		return toRPCErr(nse.Err)
 	}
-	cs.attempt.s = s
-	cs.attempt.p = &parser{r: s}
+	a.s = s
+	a.p = &parser{r: s}
 	return nil
 }
 
@@ -456,7 +486,7 @@ type clientStream struct {
 
 	retryThrottler *retryThrottler // The throttler active when the RPC began.
 
-	binlog *binarylog.MethodLogger // Binary logger, can be nil.
+	binlog binarylog.MethodLogger // Binary logger, can be nil.
 	// serverHeaderBinlogged is a boolean for whether server header has been
 	// logged. Server header will be logged when the first time one of those
 	// happens: stream.Header(), stream.Recv().
@@ -508,6 +538,11 @@ type csAttempt struct {
 
 	statsHandler stats.Handler
 	beginTime    time.Time
+
+	// set for newStream errors that may be transparently retried
+	allowTransparentRetry bool
+	// set for pick errors that are returned as a status
+	drop bool
 }
 
 func (cs *clientStream) commitAttemptLocked() {
@@ -527,41 +562,21 @@ func (cs *clientStream) commitAttempt() {
 // shouldRetry returns nil if the RPC should be retried; otherwise it returns
 // the error that should be returned by the operation.  If the RPC should be
 // retried, the bool indicates whether it is being retried transparently.
-func (cs *clientStream) shouldRetry(err error) (bool, error) {
-	if cs.attempt.s == nil {
-		// Error from NewClientStream.
-		nse, ok := err.(*transport.NewStreamError)
-		if !ok {
-			// Unexpected, but assume no I/O was performed and the RPC is not
-			// fatal, so retry indefinitely.
-			return true, nil
-		}
+func (a *csAttempt) shouldRetry(err error) (bool, error) {
+	cs := a.cs
 
-		// Unwrap and convert error.
-		err = toRPCErr(nse.Err)
-
-		// Never retry DoNotRetry errors, which indicate the RPC should not be
-		// retried due to max header list size violation, etc.
-		if nse.DoNotRetry {
-			return false, err
-		}
-
-		// In the event of a non-IO operation error from NewStream, we never
-		// attempted to write anything to the wire, so we can retry
-		// indefinitely.
-		if !nse.DoNotTransparentRetry {
-			return true, nil
-		}
-	}
-	if cs.finished || cs.committed {
-		// RPC is finished or committed; cannot retry.
+	if cs.finished || cs.committed || a.drop {
+		// RPC is finished or committed or was dropped by the picker; cannot retry.
 		return false, err
 	}
+	if a.s == nil && a.allowTransparentRetry {
+		return true, nil
+	}
 	// Wait for the trailers.
 	unprocessed := false
-	if cs.attempt.s != nil {
-		<-cs.attempt.s.Done()
-		unprocessed = cs.attempt.s.Unprocessed()
+	if a.s != nil {
+		<-a.s.Done()
+		unprocessed = a.s.Unprocessed()
 	}
 	if cs.firstAttempt && unprocessed {
 		// First attempt, stream unprocessed: transparently retry.
@@ -573,14 +588,14 @@ func (cs *clientStream) shouldRetry(err error) (bool, error) {
 
 	pushback := 0
 	hasPushback := false
-	if cs.attempt.s != nil {
-		if !cs.attempt.s.TrailersOnly() {
+	if a.s != nil {
+		if !a.s.TrailersOnly() {
 			return false, err
 		}
 
 		// TODO(retry): Move down if the spec changes to not check server pushback
 		// before considering this a failure for throttling.
-		sps := cs.attempt.s.Trailer()["grpc-retry-pushback-ms"]
+		sps := a.s.Trailer()["grpc-retry-pushback-ms"]
 		if len(sps) == 1 {
 			var e error
 			if pushback, e = strconv.Atoi(sps[0]); e != nil || pushback < 0 {
@@ -597,10 +612,10 @@ func (cs *clientStream) shouldRetry(err error) (bool, error) {
 	}
 
 	var code codes.Code
-	if cs.attempt.s != nil {
-		code = cs.attempt.s.Status().Code()
+	if a.s != nil {
+		code = a.s.Status().Code()
 	} else {
-		code = status.Convert(err).Code()
+		code = status.Code(err)
 	}
 
 	rp := cs.methodConfig.RetryPolicy
@@ -645,19 +660,24 @@ func (cs *clientStream) shouldRetry(err error) (bool, error) {
 }
 
 // Returns nil if a retry was performed and succeeded; error otherwise.
-func (cs *clientStream) retryLocked(lastErr error) error {
+func (cs *clientStream) retryLocked(attempt *csAttempt, lastErr error) error {
 	for {
-		cs.attempt.finish(toRPCErr(lastErr))
-		isTransparent, err := cs.shouldRetry(lastErr)
+		attempt.finish(toRPCErr(lastErr))
+		isTransparent, err := attempt.shouldRetry(lastErr)
 		if err != nil {
 			cs.commitAttemptLocked()
 			return err
 		}
 		cs.firstAttempt = false
-		if err := cs.newAttemptLocked(isTransparent); err != nil {
+		attempt, err = cs.newAttemptLocked(isTransparent)
+		if err != nil {
+			// Only returns error if the clientconn is closed or the context of
+			// the stream is canceled.
 			return err
 		}
-		if lastErr = cs.replayBufferLocked(); lastErr == nil {
+		// Note that the first op in the replay buffer always sets cs.attempt
+		// if it is able to pick a transport and create a stream.
+		if lastErr = cs.replayBufferLocked(attempt); lastErr == nil {
 			return nil
 		}
 	}
@@ -667,7 +687,10 @@ func (cs *clientStream) Context() context.Context {
 	cs.commitAttempt()
 	// No need to lock before using attempt, since we know it is committed and
 	// cannot change.
-	return cs.attempt.s.Context()
+	if cs.attempt.s != nil {
+		return cs.attempt.s.Context()
+	}
+	return cs.ctx
 }
 
 func (cs *clientStream) withRetry(op func(a *csAttempt) error, onSuccess func()) error {
@@ -697,7 +720,7 @@ func (cs *clientStream) withRetry(op func(a *csAttempt) error, onSuccess func())
 			cs.mu.Unlock()
 			return err
 		}
-		if err := cs.retryLocked(err); err != nil {
+		if err := cs.retryLocked(a, err); err != nil {
 			cs.mu.Unlock()
 			return err
 		}
@@ -728,7 +751,7 @@ func (cs *clientStream) Header() (metadata.MD, error) {
 		cs.binlog.Log(logEntry)
 		cs.serverHeaderBinlogged = true
 	}
-	return m, err
+	return m, nil
 }
 
 func (cs *clientStream) Trailer() metadata.MD {
@@ -746,10 +769,9 @@ func (cs *clientStream) Trailer() metadata.MD {
 	return cs.attempt.s.Trailer()
 }
 
-func (cs *clientStream) replayBufferLocked() error {
-	a := cs.attempt
+func (cs *clientStream) replayBufferLocked(attempt *csAttempt) error {
 	for _, f := range cs.buffer {
-		if err := f(a); err != nil {
+		if err := f(attempt); err != nil {
 			return err
 		}
 	}
@@ -797,22 +819,17 @@ func (cs *clientStream) SendMsg(m interface{}) (err error) {
 	if len(payload) > *cs.callInfo.maxSendMessageSize {
 		return status.Errorf(codes.ResourceExhausted, "trying to send message larger than max (%d vs. %d)", len(payload), *cs.callInfo.maxSendMessageSize)
 	}
-	msgBytes := data // Store the pointer before setting to nil. For binary logging.
 	op := func(a *csAttempt) error {
-		err := a.sendMsg(m, hdr, payload, data)
-		// nil out the message and uncomp when replaying; they are only needed for
-		// stats which is disabled for subsequent attempts.
-		m, data = nil, nil
-		return err
+		return a.sendMsg(m, hdr, payload, data)
 	}
 	err = cs.withRetry(op, func() { cs.bufferForRetryLocked(len(hdr)+len(payload), op) })
 	if cs.binlog != nil && err == nil {
 		cs.binlog.Log(&binarylog.ClientMessage{
 			OnClientSide: true,
-			Message:      msgBytes,
+			Message:      data,
 		})
 	}
-	return
+	return err
 }
 
 func (cs *clientStream) RecvMsg(m interface{}) error {
@@ -1364,8 +1381,10 @@ func (as *addrConnStream) finish(err error) {
 
 // ServerStream defines the server-side behavior of a streaming RPC.
 //
-// All errors returned from ServerStream methods are compatible with the
-// status package.
+// Errors returned from ServerStream methods are compatible with the status
+// package.  However, the status code will often not match the RPC status as
+// seen by the client application, and therefore, should not be relied upon for
+// this purpose.
 type ServerStream interface {
 	// SetHeader sets the header metadata. It may be called multiple times.
 	// When call multiple times, all the provided metadata will be merged.
@@ -1428,7 +1447,7 @@ type serverStream struct {
 
 	statsHandler stats.Handler
 
-	binlog *binarylog.MethodLogger
+	binlog binarylog.MethodLogger
 	// serverHeaderBinlogged indicates whether server header has been logged. It
 	// will happen when one of the following two happens: stream.SendHeader(),
 	// stream.Send().
@@ -1448,11 +1467,20 @@ func (ss *serverStream) SetHeader(md metadata.MD) error {
 	if md.Len() == 0 {
 		return nil
 	}
+	err := imetadata.Validate(md)
+	if err != nil {
+		return status.Error(codes.Internal, err.Error())
+	}
 	return ss.s.SetHeader(md)
 }
 
 func (ss *serverStream) SendHeader(md metadata.MD) error {
-	err := ss.t.WriteHeader(ss.s, md)
+	err := imetadata.Validate(md)
+	if err != nil {
+		return status.Error(codes.Internal, err.Error())
+	}
+
+	err = ss.t.WriteHeader(ss.s, md)
 	if ss.binlog != nil && !ss.serverHeaderBinlogged {
 		h, _ := ss.s.Header()
 		ss.binlog.Log(&binarylog.ServerHeader{
@@ -1467,6 +1495,9 @@ func (ss *serverStream) SetTrailer(md metadata.MD) {
 	if md.Len() == 0 {
 		return
 	}
+	if err := imetadata.Validate(md); err != nil {
+		logger.Errorf("stream: failed to validate md when setting trailer, err: %v", err)
+	}
 	ss.s.SetTrailer(md)
 }
 

vendor/google.golang.org/grpc/version.go

@@ -19,4 +19,4 @@
 package grpc
 
 // Version is the current grpc version.
-const Version = "1.45.0"
+const Version = "1.47.0"